Dactyloscopist Fingerprint expert

Evidence 3 different kinds of fingerprints Latent Prints Patent Prints Plastic Prints

Latent Prints A chance or accidental impression left by skin on a surface Chemical, Electronic, and physical processing techniques show visualization of the invisible print Print comes comes from sweat, motor oil, blood, paint, ink… Very valuable physical evidence

Latent Print

Patent Prints Friction ridge impressions of unknown origins Transfer from a foreign material on a finger onto a surface Visible Photographed rather than lifted Ex: ink, dirt, blood…

Patent Prints

Plastic Prints Friction ridge impression from Finger Palm Toe Foot Keeps the shape of the ridge detail Ex: melted candle wax, thick grease Visible and doesn’t need photography

Plastic Prints

Fingerprint Capture The machine mainly determines the difference in the ridges and the valleys Two kinds of readers Solid-state fingerprint reader Optical fingerprint reader

Classifying fingerprints 4 different kinds of fingerprints: Arch Loop Whorl Tented Arch

Arch

Loop

Whorl

Tented Arch

Case Study: Conviction Through Enhanced Fingerprint Identification In 1990 an unknown assailant sexually molested and fatally stabbed a young woman. The only evidence was a pillowcase, found next to the victims body. It had several blood stains, one stain showed some faint fingerprint ridge detail.

Investigation Pillowcase to the departments forensic unit for bloodstain pattern analysis Stains were consistent with a knife blade Fingerprint had enough ridge detail to go further into the investigation Image enhancement developed likely suspects and the the DNA proved the fingerprint match was correct

Interview “What kind of educational background do you have to have in order to work as a fingerprint expert?” “It depends, there are different levels. There is on the job training and job preparation training; NCIC National Crime Index Certification and International Association of Identification. The person with the least amount of experience has worked here for 7 years.”

“What is a typical day like for you?” “It depends, I examine fingerprints of individuals that are arrested and process their identification to check their previous arrest history. I also review the work of coworkers to make sure they make proper identifications.”

“Are you a forensic specialist all the time or do you have a "day job" “There are different shifts. There is a late unit and a temperate unit which is 24 hours. There are three 8 hour shifts each day. There is a shift from 4am to 3 pm.”

Resources http://images.google.com/imgres?imgurl=http://www.fdle.state.fl.us/CrimeLab/images/fingerprint http://www.wilsonnc.org/userimages/image/00000023_image002.jpg http://en.wikipedia.org/wiki/Fingerprint#Patent_prints http://static.howstuffworks.com/gif/safecracking-keypad.jpg http://people.pwf.cam.ac.uk/jw566/research/photex/application/images/finger1.jpg http://www.crimeandclues.com/92dec001.htm