1. 8 th Grade Forensic Science T. Trimpe 2006 http://sciencespot.net

2. Fingerprint Principles According to criminal investigators, fingerprints follow 3 fundamental principles: 1. A fingerprint is an individual characteristic; no two people have been found with the exact same fingerprint pattern-but there are extremely close ones that are very similar

3. 2. A fingerprint pattern will remain unchanged for the life of an individual; however, the print itself may change due to permanent scars and skin diseases. 3. Fingerprints have general characteristic ridge patterns that allow them to be systematically identified.

4. Three Kinds of CRIME-SCENE Prints LATENT PRINT (hidden print) is a misnomer but often used inclusively. There are actually three kinds of CRIME-SCENE prints. These are: –1. VISIBLE PRINTS which are prints made by fingers touching a surface after the ridges have been in contact with a colored material such as blood, paint, grease, or ink. –2. PLASTIC PRINTS which are ridge impressions left on a soft material such as putty, wax, soap, or dust. –3. True LATENT PRINTS which are invisible print impressions caused by the perspiration on the ridges of one’s skin coming in contact with a surface and making an invisible impression on it. Perspiration contains water, salt, amino acids, or oils and easily allows impressions to be made.

5. 1.VISIBLE PRINTS which are prints made by fingers touching a surface after the ridges have been in contact with a colored material such as blood, paint, grease, or ink

6. 2. PLASTIC PRINTS which are ridge impressions left on a soft material such as putty, wax, soap, or dust.

7. 3. True LATENT PRINTS which are invisible print impressions caused by the perspiration on the ridges of one’s skin coming in contact with a surface and making an invisible impression on it. Perspiration contains water, salt, amino acids, or oils and easily allows impressions to be made.

8. Fingerprint Classes There are 3 specific classes for all fingerprints based upon their visual pattern: arches, loops, and whorls. Each group is divided into smaller groups as seen in the lists below. Arch Plain arch Tented arch Loop Radial Loop Ulnar loop Whorl Plain whorl Central pocket whorl Double loop whorl Accidentical

9. Interesting Info Did you know? Dactyloscopy is the study of fingerprint identification. Police investigators are experts in collecting “dactylograms”, otherwise known as fingerprints. Fingerprint Factoid: 60% of people have loops, 35% have whorls, and 5% have arches

10. Arches Arches are the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other. No deltas are present. Plain Arch Ridges enter on one side and exit on the other side. Tented Arches Similar to the plain arch, but has a spike in the center. Spike or “tent”

11. Loops Loops must have one delta and one or more ridges that enter and leave on the same side. These patterns are named for their positions related to the radius and ulna bones, i.e. the bone the loop opening is facing towards. Delta L – Radial Loop R - Ulnar Loop L – Ulnar Loop R - Radial Loop Radius Ulna Left Hand X-Ray Imagine: http://www.tooloop.com/wp-content/uploads/2013/12/Radius-Ulna-X-Ray.jpg

12. Whorls Whorls have at least one ridge that makes (or tends to make) a complete circuit. They also have at least two deltas. If a print has more than two deltas, it is most likely an accidental. Draw a line between the two deltas in the plain and central pocket whorls. If some of the curved ridges touch the line, it is a plain whorl. If none of the center core touches the line, it is a central pocket whorl. Plain Whorl Central Pocket Whorl

13. Whorls – Part 2 Accidental Whorl Accidental whorls contain two or more patterns (not including the plain arch), or does not clearly fall under any of the other categories. Double Loop Whorl Double loop whorls are made up of any two loops combined into one print. Delta

14. Identify each fingerprint pattern. Right Hand Left Hand Right Hand

16. The most common techniques used to find latent or hidden fingerprints 1. Dusting with Carbon Powder on white or light colored surfaces.Carbon Powder 2. Dusting with Lanconide Powder(white) for black surfaces.Lanconide Powder 3. Dusting with Aluminum Powder for hard or dark colored surfaces as well as mirrors and metal surfaces.Aluminum Powder 4. Use of Cyanoacrylate (Super-glue) fuming.Cyanoacrylate (Super-glue) fuming. 5. Use of Iodine fuming techniques.Iodine fuming techniques. 6. Use of ninhydrin.(chemical spray)ninhydrin. 7. Use of Silver Nitrate(reaction turns print black). 8. Use of Laser technology.

17. Tools Optical scanners identify the print using light; depending on the brightness of the reflected light, optical scanners depict ridges as dark and valleys as light. Capacitance scanners determine the print by using an electrical current. Valleys and ridges on the fingers produce different voltage output, allowing for discrimination between them.

18. Tools A number of portable fingerprint scanners were developed mainly by computer companies to provide a secure access for the users. In 1998, Compaq was the first to have a print reader attached to the computer

19. Tools Some companies, police offices, and high- security government buildings require fingerprint identification for access to the building or its selected parts. In order to protect sensitive data, some businesses and the military often use scanners that are attached to computers (the U-Match mouse, for example) or installed in keyboards. These provide either immediate identification for access to the terminal or remote identification for access to secure documents or archives.

20. Tools New scanner trials are on the way to provide the same protection for e- commerce and Internet banking in order to secure transactions.Internet banking In order to combat cell phone thefts, the industry is considering equipping phones with fingerprint readers.

21. Five U.S. airports, including Chicago's O'Hare have installed finger-print scanners to check employees' backgrounds. Some banks use fingerprint scans before a check is cashed. Similarly, government agencies sometimes utilize fingerprint scans to ensure that payments are given to the proper recipients.