Powder Analysis
WHAT IS THAT WHITE POWDER? A forensic scientist may discover powder at a crime scene. In order to determine if it is illegal or not the crime lab will identify the substance using chemistry. Take on the role of a forensic chemist to identify unknown substances. The following materials will be necessary for your investigation:
  • Pencil
  • White Chalk
  • Sheet of white paper
  • Magnifying glass
  • Measuring spoons
  • Eyedropper
  • Baking Soda
  • Water
  • Sugar
  • 4 small jars
  • Salt
  • Iodine Solution
  • Cornstarch
  • Dish Towel
  • 4 sheets of black construction paper
  • Vinegar
Become a Forensic Chemist by following these procedures and filling in the Powder Analysis Chart with your results below:
Substance Appearance Texture Smell Reaction to Water Reaction to Iodine Reaction to Vinegar
Baking Soda
  1. Complete the appearance, texture, and smell activities before opening the vinegar and iodine bottles.
  2. Place one-fourth teaspoon (1 ml) of the four white powders on a sheet of black construction paper. Label the powders with the white chalk or white crayon.
  3. Study the powders with the magnifying glass. Examine what each powder looks like. How would you describe the powder's shape. Does it have large or small grains? Your observations should be written in the appearance column of the chart.
  4. Examine the powders further by rubbing each powder between your fingers. Describe how each powder feels in the Texture column of the chart.
  5. Determine if there is a smell to any of the powders. Record your findings in the Smell column of the chart.
  6. Take the eyedropper and place a drop of water on each individual powder. Examine what happens? Do the powders dissolve? Is there a reaction? Write your observations in the Reaction to Water column.
  7. Place one-half teaspoon (2ml) of each powder in a separate jar. Add 2 drops of iodine to each jar using the eyedropper. Record what happens in the Reaction to Iodine column. Iodine should be handled with care.
  8. Comparing test results of substances that are known help Forensic Scientists identify unknown substances.
  9. After analyzing and recording results of each substance have your partner leave the area. Select and place one of the powders on construction paper and do not tell which substance it is. Invite your partner back to see if she/he can determine the powder by performing the same experiments and observations previously done. Change places so your partner can select one of the powders for you to identify. Can you correctly identify the mystery powder?
  10. View the powders under a microscope. What can you observe?
Fingerprinting, Part 1
The History of Fingerprints Your Assignment
  1. What is Dactyloscopy?
  2. Why were fingerprints used in Ancient Babylon?
  3. When and why were fingerprints first used in the United States?
  4. In which country were fingerprints used to identify a woman who murdered her two sons?
  5. Which state in the United States first used fingerprints for criminals?
  6. What famous criminal case made fingerprinting the standard for personal identification?
  7. Make a full-color timeline (you can use the magazines for pictures) of fingerprinting in the world. Put it on two colored pieces of paper and include at least 10 events.
Why Fingerprint Identification? Fingerprints offer an infallible means of personal identification. That is the essential explanation for fingerprints having replaced other methods of establishing the identities of criminals reluctant to admit previous arrests. The science of fingerprint Identification stands out among all other forensic sciences for many reasons, including the following:
  • Has served governments worldwide for over 100 years to provide accurate identification of criminals. No two fingerprints have ever been found alike in many billions of human and automated computer comparisons.  Fingerprints are the very basis for criminal history foundation at every police agency on earth.

  • Established the first forensic professional organization, the International Association for Identification (IAI), in 1915.

  • Established the first professional certification program for forensic scientists, the IAI's Certified Latent Print Examiner program (in 1977), issuing certification to those meeting stringent criteria and revoking certification for serious errors such as erroneous identifications.

  • Remains the most commonly used forensic evidence worldwide - in most jurisdictions fingerprint examination cases match or outnumber all other forensic examination casework combined.

  • Continues to expand as the premier method for positively identifying persons, with tens of thousands of persons added to fingerprint repositories daily in America alone - far outdistancing similar databases in growth.

  • Worldwide, fingerprints harvested from crime "scenes lead to more suspects and generate more evidence in court than all other forensic laboratory techniques combined. "

Other visible human characteristics tend to change - fingerprints do not.  Barring injuries or surgery causing deep scarring, or diseases such as leprosy damaging the formative layers of friction ridge skin (injuries, scarring and diseases tend to exhibit telltale indicators of unnatural change), finger and palm print features have never been shown to move about or change their unit relationship throughout the life of a person. In earlier civilizations, branding and even maiming were used to mark the criminal for what he or she was. The thief was deprived of the hand which committed the thievery. Ancient Romans employed the tattoo needle to identify and prevent desertion of mercenary soldiers. Before the mid-1800s, law enforcement officers with extraordinary visual memories, so-called "camera eyes," identified previously arrested offenders by sight. Photography lessened the burden on memory but was not the answer to the criminal identification problem. Personal appearances change. Around 1870, French anthropologist Alphonse Bertillon devised a system to measure and record the dimensions of certain bony parts of the body. These measurements were reduced to a formula which, theoretically, would apply only to one person and would not change during his/her adult life. The Bertillon System was generally accepted for thirty years. But it never recovered from the events of 1903, when a man named Will West was sentenced to the U.S. Penitentiary at Leavenworth, Kansas. It was discovered that there was already a prisoner at the penitentiary at the time, whose Bertillon measurements were nearly the same, and his name was William West. Upon investigation, there were indeed two men who looked exactly alike. Their names were Will and William West respectively. Their Bertillon measurements were close enough to identify them as the same person. However, a fingerprint comparison quickly and correctly identified them as two different people. (Per prison records discovered later, the West men were apparently identical twin brothers and each had a record of correspondence with the same immediate family relatives.)
PrehistoricPicture writing of a hand with ridge patterns was discovered in Nova Scotia. In ancient Babylon, fingerprints were used on clay tablets for business transactions. In ancient China, thumb prints were found on clay seals.
Chinese Clay Seal
In 14th century Persia, various official government papers had fingerprints (impressions), and one government official, a doctor, observed that no two fingerprints were exactly alike.
Marcella Malpighi Malpighi 1686 - Malpighi In 1686, Marcello Malpighi, an anatomy professor at the University of Bologna, noted in his treatise; ridges, spirals and loops in fingerprints. He made no mention of their value as a tool for individual identification. A layer of skin was named after him; "Malpighi" layer, which is approximately 1.8mm thick.
Prof Purkinje
1823 - PurkinjeIn 1823, John Evangelist Purkinje, an anatomy professor at the University of Breslau, published his thesis discussing nine fingerprint patterns, but he too made no mention of the value of fingerprints for personal identification.
Sir Wm. Herschel
Herschel Herschel's FPs recorded over a period of 57 yrs Herschel's fingerprints recorded over a period of 57 years
1858 - Herschel The English first began using fingerprints in July of 1858, when Sir William James Herschel, Chief Magistrate of the Hooghly district in Jungipoor, India, first used fingerprints on native contracts. On a whim, and without thought toward personal identification, Herschel had Rajyadhar Konai, a local businessman, impress his hand print on a contract. The idea was merely "... to frighten [him] out of all thought of repudiating his signature." The native was suitably impressed, and Herschel made a habit of requiring palm prints--and later, simply the prints of the right Index and Middle fingers--on every contract made with the locals. Personal contact with the document, they believed, made the contract more binding than if they simply signed it. Thus, the first wide-scale, modern-day use of fingerprints was predicated, not upon scientific evidence, but upon superstitious beliefs. As his fingerprint collection grew, however, Herschel began to note that the inked impressions could, indeed, prove or disprove identity. While his experience with fingerprinting was admittedly limited, Sir William Herschel's private conviction that all fingerprints were unique to the individual, as well as permanent throughout that individual's life, inspired him to expand their use.
1863 - Coulier Professor Paul-Jean Coulier, of Val-de-Grâce in Paris, publishes his observations that (latent) fingerprints can be developed on paper by iodine fuming, explains how to preserve (fix) such developed impressions and mentions the potential for identifying suspects' fingerprints by use of a magnifying glass.   3, 4
Dr. Henry Faulds
1880 - Faulds - First Latent Print Identification During the 1870s, Dr. Henry Faulds, the British Surgeon-Superintendent of Tsukiji Hospital in Tokyo, Japan, took up the study of "skin-furrows" after noticing finger marks on specimens of "prehistoric" pottery. A learned and industrious man, Dr. Faulds not only recognized the importance of fingerprints as a means of identification, but devised a method of classification as well.In 1880, Faulds forwarded an explanation of his classification system and a sample of the forms he had designed for recording inked impressions, to Sir Charles Darwin. Darwin, in advanced age and ill health, informed Dr. Faulds that he could be of no assistance to him, but promised to pass the materials on to his cousin, Francis Galton. Also in 1880, Dr. Henry Faulds published an article in the Scientific Journal, "Nature" (nature). He discussed fingerprints as a means of personal identification, and the use of printers ink as a method for obtaining such fingerprints. He is also credited with the first fingerprint identification of a greasy fingerprint left on an alcohol bottle.
Gilbert Thompson Portrait
1882 - Thompson
In 1882, Gilbert Thompson of the U.S. Geological Survey in New Mexico, used his own thumb print on a document to prevent forgery. This is the first known use of fingerprints in the United States.  Click the image below to see a larger image of an 1882 receipt issued by Gilbert Thompson to "Lying Bob" in the amount of 75 dollars.
Thompson Receipt
Alphonse Bertillon 1882 - Bertillon Alphonse Bertillon, a Clerk in the Prefecture of Police of at Paris, France, devised a system of classification, known as Anthropometry or the Bertillon System, using measurements of parts of the body.  Bertillon's system included measurements such as head length, head width, length of the middle finger, length of the left foot;  and length of the forearm from the elbow to the tip of the middle finger.
Diagram of Bertillon Measurements blank space Forearm Measurement blank space Forearm Measurement Overhead View
In 1888 Bertillon was made Chief of the newly created Department of Judicial Identity where he used anthropometry as the primary means of identification. He later introduced Fingerprints but relegated them to a secondary role in the category of special marks.
Samuel L. Clemens Twain (Clemens) 1883 - Mark Twain (Samuel L. Clemens) In Mark Twain's book, "Life on the Mississippi", a murderer was identified by the use of fingerprint identification. In a later book by Mark Twain, "Pudd'n Head Wilson", there was a dramatic court trial on fingerprint identification. A more recent movie was made from this book.
Sir Francis Galton Galton 1888 - Galton Sir Francis Galton, a British anthropologist and a cousin of Charles Darwin, began his observations of fingerprints as a means of identification in the 1880's.
Juan Vucetich 1891 - Vucetich Juan Vucetich, an Argentine Police Official, began the first fingerprint files based on Galton pattern types. At first, Vucetich included the Bertillon System with the files.
Juan Vucetich thumb print and signature Right Thumb Impression and Signature of Juan Vucetich
Buenos Aires Police Logo 1892 - Vucetich & Galton Juan Vucetich made the first criminal fingerprint identification in 1892. He was able to identify Francis Rojas, a woman who murdered her two sons and cut her own throat in an attempt to place blame on another. Her bloody print was left on a door post, proving her identity as the murderer. Francis Rojas' inked fingerprints Francis Rojas' Inked Fingerprints Sir Francis Galton published his book, "Fingerprints", establishing the individuality and permanence of fingerprints. The book included the first classification system for fingerprints. Galton's primary interest in fingerprints was as an aid in determining heredity and racial background. While he soon discovered that fingerprints offered no firm clues to an individual's intelligence or genetic history, he was able to scientifically prove what Herschel and Faulds already suspected: that fingerprints do not change over the course of an individual's lifetime, and that no two fingerprints are exactly the same. According to his calculations, the odds of two individual fingerprints being the same were 1 in 64 billion. Galton identified the characteristics by which fingerprints can be identified. A few of these same characteristics (minutia) are basically still in use today, and are sometimes referred to as Galton Details.
Azizul Haque Haque 1897 - Haque & Bose On 12 June 1897, the Council of the Governor General of India approved a committee report that fingerprints should be used for classification of criminal records. Later that year, the Calcutta (now Kolkata) Anthropometric Bureau became the world's first Fingerprint Bureau. Working in the Calcutta Anthropometric Bureau (before it became the Fingerprint Bureau) were Azizul Haque and Hem Chandra Bose. Haque and Bose are the two Indian fingerprint experts credited with primary development of the Henry System of fingerprint classification (named for their supervisor, Edward Richard Henry). The Henry classification system is still used in English-speaking countries (primarily as the manual filing system for accessing paper archive files that have not been scanned and computerized).
Sir Edward Richard Henry Henry 1900 - Henry The United Kingdom Home Secretary Office conducted an inquiry into "Identification of Criminals by Measurement and Fingerprints." Mr. Edward Richard Henry (later Sir ER Henry) appeared before the inquiry committee to explain the system published in his recent book "The Classification and Use of Fingerprints." The committee recommended adoption of fingerprinting as a replacement for the relatively inaccurate Bertillon system of anthropometric measurement, which only partially relied on fingerprints for identification.
Met Police Crest 1901 - Henry The Fingerprint Branch at New Scotland Yard (London Metropolitan Police) was created in July 1901 using the Henry System of Fingerprint Classification.
1902 First systematic use of fingerprints in the U.S. by the New York Civil Service Commission for testing. Dr. Henry P. DeForrest pioneers U.S. fingerprinting.
1903 The New York State Prison system began the first systematic use of fingerprints in the U.S. for criminals.
1904 The use of fingerprints began in Leavenworth Federal Penitentiary in Kansas, and the St. Louis Police Department. They were assisted by a Sergeant from Scotland Yard who had been on duty at the St. Louis World's Fair Exposition guarding the British Display. Sometime after the St. Louis World's Fair, the International Association of Chiefs of Police (IACP) created America's first national fingerprint repository, called the National Bureau of Criminal Identification.
US Army Seal 1905 U.S. Army begins using fingerprints. U.S. Department of Justice forms the Bureau of Criminal Identification in Washington, DC to provide a centralized reference collection of fingerprint cards. Two years later the U.S. Navy started, and was joined the next year by the Marine Corp. During the next 25 years more and more law enforcement agencies join in the use of fingerprints as a means of personal identification. Many of these agencies began sending copies of their fingerprint cards to the National Bureau of Criminal Identification, which was established by the International Association of Police Chiefs.
US Navy Seal 1907 U.S. Navy begins using fingerprints. U.S. Department of Justice's Bureau of Criminal Identification moves to Leavenworth Federal Penitentiary where it is staffed at least partially by inmates.
USMC Seal 1908 U.S. Marine Corps begins using fingerprints.
IAI Logo 1915 Inspector Harry H. Caldwell of the Oakland, California Police Department's Bureau of Identification wrote numerous letters to "Criminal Identification Operators" in August 1915, requesting them to meet in Oakland for the purpose of forming an organization to further the aims of the identification profession. In October 1915, a group of twenty-two identification personnel met and initiated the "International Association for Criminal Identification" In 1918, the organization was renamed the International Association for Identification (IAI) due to the volume of non-criminal identification work performed by members. Sir Francis Galton's right index finger appears in the IAI logo. The IAI's official publication is the Journal of Forensic Identification.
Edmond Locard 1918 Edmond Locard wrote that if 12 points (Galton's Details) were the same between two fingerprints, it would suffice as a positive identification. Locard's 12 points seems to have been based on an unscientific "improvement" over the eleven anthropometric measurements (arm length, height, etc.) used to "identify" criminals before the adoption of fingerprints.
FBI Seal 1924 In 1924, an act of congress established the Identification Division of the FBI. The IACP's National Bureau of Criminal Identification and the US Justice Department's Bureau of Criminal Identification consolidated to form the nucleus of the FBI fingerprint files. 1946 By 1946, the FBI had processed 100 million fingerprint cards in manually maintained files; and by 1971, 200 million cards. With the introduction of automated fingerprint identification system (AFIS) technology, the files were split into computerized criminal files and manually maintained civil files. Many of the manual files were duplicates though, the records actually represented somewhere in the neighborhood of 25 to 30 million criminals, and an unknown number of individuals in the civil files.
Logo of The Fingerprint Society The Fingerprint Society 1974 In 1974, four employees of the Hertfordshire (United Kingdom) Fingerprint Bureau contacted fingerprint experts throughout the UK and began organization of that country's first professional fingerprint organization, the National Society of Fingerprint Officers. The organization initially consisted of only UK experts, but quickly expanded to international scope and was renamed The Fingerprint Society in 1977. The initials F.F.S. behind a fingerprint expert's name indicates they are recognized as a Fellow of the Fingerprint Society. The Society hosts annual educational conferences with speakers and delegates attending from many countries.
IAI Logo 1977 At New Orleans, Louisiana on 1 August 1977, delegates to the 62nd Annual Conference of the International Association for Identification (IAI) voted to establish the world's first certification program for fingerprint experts. Since 1977, the IAI's Latent Print Certification Board has proficiency tested thousands of applicants, and periodically proficiency tests all IAI Certified Latent Print Examiners (CLPEs). Contrary to claims (in the 1990s and later) that fingerprint experts profess their body of practitioners never make erroneous identifications, the Latent Print Certification program proposed, adopted, and in-force since 1977, specifically recognizes that such mistakes do sometimes occur, and must be addressed by the Latent Print Certification Board. During the past three decades, CLPE status has become a prerequisite for journeyman fingerprint expert positions in many US state and federal government forensic laboratories. IAI CLPE status is considered by many identification professionals to be a measurement of excellence.
2005 INTERPOL's Automated Fingerprint Identification System repository exceeds 50,000 sets fingerprints for important international criminal records from 184 member countries. Over 170 countries have 24 x 7 interface ability with INTERPOL expert fingerprint services.
Department of Homeland Security Seal 2012 The largest AFIS repository in America is operated by the Department of Homeland Security's US Visit Program, containing over 120 million persons' fingerprints, many in the form of two-finger records. The two-finger records are non-compliant with FBI and Interpol standards, but sufficient for positive identification and valuable for forensics because index fingers and thumbs are the most commonly identified crime scene fingerprints. The US Visit Program has been migrating from two flat (not rolled) fingerprints to ten flat fingerprints since 2007. "Fast capture" research will hopefully enable implementation of ten "rolled print equivalent" fingerprint recording (within 15 seconds per person fingerprinted) in future years. The largest tenprint AFIS repository in America is the FBI's Integrated AFIS (IAFIS) in Clarksburg, WV. IAFIS has more than 60 million individual computerized fingerprint records (both criminal and civil applicant records). Old paper fingerprint cards for the civil files are still manually maintained in a warehouse facility (rented shopping center space) in Fairmont, WV, though most enlisted military service member fingerprint cards received after 1990, and all military-related fingerprint cards received after 19 May 2000, have now been computerized and can be searched internally by the FBI. In "Next Generation Identification," the FBI may make civil file AFIS searches available to US law enforcement agencies through remote interface. The FBI is also planning to eventually expand their automated identification activities to include other biometrics such as palm, iris and face. All US states and many large cities have their own AFIS databases, each with a subset of fingerprint records that is not stored in any other database. Many also store and search palmprints. Law enforcement fingerprint interface standards are important to enable sharing records and reciprocal searches to identify criminals. Interpol, the European Union's Prüm Treaty, the FBI's Next Generation Identification and other initiatives seek to improve cross-jurisdiction sharing (probing and sharing/pushing) of important finger and palm print data to identify criminals.
AADHAR Logo The Future By March 2012, the Unique Identification Authority of India is scheduled to possess the world's largest fingerprint (multi-modal biometric) system, with over 200 million fingerprint, face and iris biometric records. UIAI plans to collect as many as 600 million multi-modal record by the end of 2014. India's Unique Identification project is also known as Aadhaar, a word meaning "the foundation" in several Indian languages. Aadhaar is a voluntary program, with the ambitious goal of eventually providing reliable national ID documents for most of India's 1.2 billion residents. With a database many times larger than any other in the world, Aadhaar's ability to leverage automated fingerprint and iris modalities (and potentially automated face recognition) enables rapid and reliable automated searching and identification impossible to accomplish with fingerprint technology alone, especially when searching children and elderly residents' fingerprints.
Fingerprinting, Part 2

Can we invent a way to classify fingerprints?


  • The patterns of ridges on our finger pads are unique: no two individuals—even identical twins—have fingerprints that are exactly alike.
  • We leave impressions—or prints—of these patterns on everything we touch with any pressure.
  • The prints can be visible, as when our fingers are dirty or oily, or they can be latent, as when they are made only by the sweat that is always present on our finger ridges.
  • Injuries such as burns or scrapes will not change the ridge structure: when new skin grows in, the same pattern will come back.
  • Dactyloscopy is the practice of using fingerprints to identify someone.


  • Fingerprints can be classified by pattern types, by the size of those patterns, and by the position of the patterns on the finger.


  1. 3x5-inch index cards, at least two per participant
  2. pencils and a sharpener
  3. transparent tape; 3/4-inch is better than 1/2-inch
  4. good lighting
  5. hand magnifiers—nice to have but not essential
tented arch image
whorl image

Procedures and Activity


If you want to use fingerprints to solve crimes, you must have a way to describe and sort and find prints that are similar to the one you find at a crime scene. The FBI has over 200 million prints on file; they can’t look through every single one to find a match! Today we are going to look at some of our fingerprints and see how we might sort them into categories, just as fingerprint specialists do.


  1. Divide participants into groups of 2-6
  2. Rub a pencil over the central part of an index card until it is covered with graphite.
  3. Have another card for recording your prints and write your names on the lined side and turn it over.
  4. Each participant will be making prints of the index finger and the middle finger of the same hand. Start with your dominant hand.
  5. You want to make prints not of your fingertips but of the pads of their fingers, near the joint crease, because that is where the most interesting patterns are.
  6. Press and roll your finger firmly on the penciled area, then stick a short piece of tape to the finger pad area, pressing down thoroughly, remove the tape and press it onto your print record card.
  7. Immediately label your print “L” or “R” for left or right hand and “I” or “M” for index or middle finger.
  8. Repeat procedure for the second finger. Do it over until you get two good prints.
  9. After all prints are made and labeled, compare prints for similarities and differences.
    • Are the two prints from the same hand more alike than prints from different people? How?
    • What kinds of patterns do you see? Give names to the patterns (circles, triangles, curvy lines)
    • Look below for the “official” names for patterns (loops, whorls, and arches).
    • What are the positions of those patterns on the finger (how close they are to the joint line)?
    • In which direction do the loops curve—toward the thumb or toward the pinkie finger? (Remember that taped prints are like looking at your finger palm-up and inked prints are mirror images.)
    • Compare the size of those patterns (such as how many ridges make up a loop).
    Note that, while scars, such as the white line on one of the sample prints in this lesson, are the easiest patterns to see, they cannot be used either for classification or identification. They are not unique in the way that ridge patterns are, and they also change over time—making them unreliable for these purposes.
  10. In which of these groups would you look for a loop that leans to the left? Would it make sense to look through the whorls?
  11. Which is the most common pattern?  Graph the results of each type.
left loop image radial loop image right loop image

Closing - Original Question

  1. How can fingerprints be classified?
  2. How would classification make it easier to match one print against a database of many?
Look for evidence of a plan to search systematically: for example, to look through the left-leaning loops with eight ridges that are close to the finger joint.
Left-leaning loop Right-leaning loop Whorl
Double loop Double loop with central pocket
Plain arch Tented arch Arch with loop & scar
Fingerprinting, Part 3
Fingerprinting Identification Federal Bureau of Investigation Educational Web Publication For over 100 years, police agencies have had a powerful tool in combating crime. The use of fingerprinting allows crime fighters an extremely accurate means of identification. Other means of identification (such as hair color or style, weight, or eye color) may change, but fingerprints do not. In earlier civilizations, branding, tattooing, or even maiming was used to mark and identify criminals. Although man had been aware of the fact that each person possessed a unique set of ridges on the fingers and hands, the use of these prints for criminal identification was not accepted until the early 1900s. The FBI Identification Division was born in 1924, with the receipt of 810,188 fingerprint files, mostly from the Leavenworth Penitentiary. This collection became increasingly important due to the emergence of criminals who regularly crossed state lines. Currently, the FBI possesses over 250 million sets of fingerprint records. This enormous collection is composed of both criminal and civil prints. The civil file includes the prints of both government employees and applicants for federal jobs. All standard fingerprint cards are eight-inch square pieces of paper,with a thickness much like that of thin cardboard. At the present time, the FBI receives over 34,000 fingerprint cards each work day. The photograph to the right is an example of a standard FBI fingerprint card. If all of the fingerprint cards on file with the FBI were piled on top of each other, they would equal one hundred and thirty-three stacks the size of the Empire State Building! Fingerprints differ from person to person based upon distinctive patterns of ridges. There are seven different finger print patterns used for identification purposes. Latent fingerprints are difficult to see but can be made visible for examination. Any fingerprint left at a crime scene (as opposed to one which is on a fingerprint card) is known as a latent fingerprint. Latent fingerprints may be left on almost all surfaces, sometimes even on human skin. Numerous techniques are used to make latent prints visible, such as lasers, powders, alternate light sources, and a process known as "glue fuming". The West Case For many years, scientists did not use fingerprinting as a serious tool for identifying criminals. Instead, they used a system which recorded the dimensions of certain skeletal body parts (known as the Bertillon System). But in 1903, Leavenworth Federal Penitentiary received a prisoner by the name of Will West. Shockingly, Will had almost the same Bertillon measurements (as well as appearance) as another prisoner currently serving a life sentence for murder. But even though the two unrelated criminals looked identical, and had similar names, their fingerprints were, of course, different. Thanks to this remarkable case, fingerprinting became the standard for personal identification. Questions
  1. What is Dactyloscopy?
  2. Why were fingerprints used in Ancient Babylon?
  3. When and why were fingerprints first used in the United States?
  4. In which country were fingerprints used to identify a woman who murdered her two sons?
  5. Which state in the United States first used fingerprints for criminals?
  6. What famous criminal case made fingerprinting the standard for personal identification?
  7. How many methods are there for taking fingerprints?
  8. How do we classify fingerprints?
The Teeth Can Tell


Forensic dentists assist in crime solving by studying teeth and teeth impressions. Dental records are often used to identify people. Because teeth are one of the hardest substances in the human body, they are frequently well preserved. Dental x-rays or records showing fillings, position of teeth, etc. can help forensic dentists find a match of teeth to the individual. Eighty percent of the time teeth impressions are used to identify unknown victims. As a forensic dentist you will have the chance to match teeth impressions to discover who took the bite? Materials Lists
  • Scissors
  • Styrofoam plate
  • Marking Pen
The procedures for making teeth impressions are:
  1. Divide the styrofoam plate into six equal wedges. Cut the wedges.
  2. Take two of the wedges and stack them together. Cut off 1 inch from the pointed end of the wedges.
  3. Place the two wedges into your mouth as far as possible.
  4. Bite down on the wedges firmly and then remove them.
  5. Label the top and bottom wedges Top Teeth and Bottom Teeth.
  6. Study the teeth impressions. Count the number of teeth in the top and bottom impressions. What other characteristics of the impressions do you notice? Compare the top teeth impressions to the bottom. Are there teeth missing, spaces, chips, etc.?
  7. Practice being a forensic dentist by leaving the room. One student in the room will take a bite of thick cheese or thick chocolate. See if you can identify the individual who took the bite by comparing the impressions with the bite in the cheese or chocolate.
    Foot to Height


    The bones of the feet can tell a lot about a person. What do feet reveal about a person's height? Forensic anthropologists team up with law enforcers to help solve crimes. Bones of the feet can reveal an interesting fact about an individual. Let's combine math with forensics to see how.
    1. Create a table.
    2. List the individuals name, height, and foot length.
    3. Have some adults remove their shoes and measure their height.
    4. Measure the length of the adult's left foot from the wall to the tip of the big toe.
    5. Examine the numbers. Do you see a pattern?
    6. Divide the length of each person's left foot by his/her height. Multiply the quotient by 100. What do you get? You may also want to use the calculator on a computer for this activity.
    7. The results of your calculations should be about 15, illustrating that the length of a person's foot is approximately 15 percent of his or her height.
    8. Find out the approximate height of each of your classmates by measuring their foot and charting it on a spreadsheet. Use this proporation for your calculations: 15/100 = Length of Foot/x (person's height)
    When a forensic scientist has the length of a foot, the forensic scientist will be able to approximate the height of the individual. This works best on a full grown individual for the ratio of body parts is slightly different in growing children.
      Paper Chromatography
      What is chromatography? Chromatography (from Greek word for chromos for color) is the collective term for a family of laboratory techniques for the separation of mixtures. It involves passing a mixture which contains the analyte through a stationary phase, which separates it from other molecules in the mixture and allows it to be isolated. Which means chromatography is the physical separation of a mixture into its individual components. We can use chromatography to separate the components of inks and dyes. The process can also be used to separate the colored pigments in plants or used to determine the chemical composition of many substances. Mixture or compound? Mixture – Two or more substances that are mixed together, but not chemically combined. Compounds – Two or more elements that are chemically combined. Identify each as a mixture (M) or a compound (C). ____ Air ____ Soda pop ____ Fog ____ Table salt ____ Kool-Aid ____ Water ____ Salt water ____ Carbon Monoxide Solutions & Solubility Solutions are mixtures in which one substance is dissolved in another. The solute is the substance that is dissolved, while the solvent is the substance that does the dissolving. Solubility - A measure of how much of a given substance will dissolve in a liquid. A substance that does not dissolve in water is called insoluble. A substance that does dissolve in water is called soluble. Paper Chromatography Lab
      • Obtain the supplies you’ll need. 1 large beaker (or plastic cup), 1 small beaker (or plastic cup) filled with water, 4 pieces of filter paper, 4 black markers for testing, 4 small pieces of masking tape, pencil (to attach to the top of the filter paper), permanent marker, timer
      • Write the pen number on a piece of masking tape with a permanent marker and place it at the top of the strip.
      • Choose one of the testing markers and draw a thick line near the bottom of the filter paper - about 1⁄4 inch from the bottom.
      • Pour a small amount of water into the large cup and then hang the paper strip in the cup. Make sure the ink line does not touch the water – only the bottom of the filter paper.
      • Allow the water to move up the paper for 5 minutes and then remove the strip from the water. Hang it on the side of the table to dry.
      • Follow these directions to test the other pens.
      Hair & Fiber Lab
      Hair Evidence Lab
      A. Pull out a strand of your hair and examine it with a hand lens. You may need to put it on a piece of white or
      black paper to make it easier to see.
      What does the root look like? Choose one.
      Other: _______________________
      What does the tip look like? Choose one.
      Other: _______________________
      What color is it? _______________
      Is the color the same everywhere along the shaft? ________________________
      B. Place your hair on a slide and view the shaft at low, medium, and high power. Draw the three sketches.
      C. Place your hair on a slide and view the root at low, medium, and high power. Draw the three sketches.
      D. Locate the three primary structures of your hair and choose the best description for each feature.
      Cuticle Scales
      • Flat and smooth
      • Protruding or spiky
      • Other: ___________________
      Cortex Thickness
      • Thick
      • Thin
      Cortex Color
      • Same color throughout
      • Different colors – Explain: ____________________
      Medulla Style
      • Broken
      • Continuous
      Medulla Thickness
      • Thick
      • Thin
      Medulla Transparency
      • Transparent
      • Semi-transparent
      • Opaque
      E. Compare your hair sample to one from a classmate. How is it similar? How is it different?
      F. Examine at least four animal hairs provided by your teacher. Draw a sketch of the hair at 100X magnification and write down any unique characteristics you observe that help you tell the hairs apart.
      G. Write a paragraph that compares the human and animal hair samples you examined. What differences did you notice? What characteristics could you use to identify the hair samples?
      Tool Mark Challenge
      Tool Mark Challenge Materials Needed
      • 12 tools (2-4 different types)
      • Rulers
      • Molding Clay (Dark blue or green works well)
      • Small plates
      Preparation: Label the tools with numbers and use clay to make impressions for your challenge. If you are going to use the clay impressions for the challenge, place each one in a plastic bag and label with a letter. Procedure: Goal: Your group will need to examine and document the tool marks made by each of the 12 tools. For each tool, you will need to:
      1. To prepare for the lab, roll the modeling clay into a flat circle that fits inside the plastic plate. Make several impressions of each tool in your slab of modeling clay.
      2. Use the ruler to record the measurements for each tool and its impression surfaces.
      3. Document any unique characteristics you notice on each tool or its impression. Write your observations on your worksheet.
      Features to analyze:
      • Width of tip, in mm
      • Length of tip, in mm
      • Ridges or striation patterns
      • Defects, such as nicks and chips
      • Paint chips or metal shards left on a tool
      Identification: Finally, ask the instructor for impressions left behind by some or all of the tools. Identify each of the marks correctly for extra credit!
      Final Project: Crime Scene
      You will be given the following evidence for the crime of a stolen lunch in the prep room:
      - Mystery powder with footprints - Half-eaten food with fingerprints - Hand-written note and hair on the note   After being given each of those clues, you will need to make a suspect list from MST teachers, then change the list depending on the new evidence. You need to follow the same procedures that you followed when you first did each of the original activities. For example, you should identify the exact shapes that you see in the fingerprints. You must produce a final suspect list of teachers, then look for evidence in their rooms of the crime. Once you have gathered any evidence, you must then narrow it down to your final suspect(s) and perform one-minute interviews. You then should bring your evidence to the judge (me) who will either issue a warrant for the arrest of the suspect(s) or deny the warrant based on inconclusive evidence.