DEVELOPMENT REVIEW The type of surface on which a fingerprint is deposited has a lot to do with the type of print that will be deposited on the physical evidence The use of sequential processing techniques can increase the number of prints found and improve the quality of the prints already developed

Fingerprint Reagents and Targets from http://www. ridgesandfurrows

Fingerprint Development techniques Amido Black: Proteins: Blue-black: Also Commassie blue DFO (1,8-diazafluoren-9-one): Proteins: Fluorescent Red- A more sensitive Ninhydrin analogue Fluorescence examination: naturally occurring chemicals and contaminants: Fluoresce without treatment with laser sensitive dyes. Gentian violet or crystal violet: fatty acid: purple color- good on sticky side of adhesive tape-Toxic- Yellow-orange laser light source (578nm): Alternate- Fuchsin- Green excitation (500nm) Iodine:good on both porous and non porous- fuming Ninhydrin: porous surfaces like cardboard, wallboard, paper, wood: amino acids: purple color=Ruhemann’s purple. Treatment with Zn chloride and lasers improve sensitivity Physical Developer: PD, SPD: Sliver based solution : porous surfaces that are wet or have been wet: sweat: gray to black Powders: smooth non porous: color depends on choice Silver nitrate: chlorides in prints: Small particle reagent : SPR: wet surfaces: molybdenum disulfide in detergent: lipids : gray deposit. Non porous surfaces. Sudan Black: non porous oily or greasy surface: lipids: blue black color Superglue or cyanoacrylate fuming: non porous surfaces: white. May be dusted with powder or washed with laser sensitive dyes such as Rhodamine G-6 Vacuum metal deposition VMD smooth non porous surfaces: gold or zinc thin film on latent See www.fbi.gov/hq/lab/fsc/backissu/jan2001/index.htm.

AUTOMATED FINGERPRINT INDENTIFICATION SYSTEM AFIS –The ability to compare a fingerprint found at the crime scent with a criminal fingerprint computer data base Cold Searches – searching a data base of several million prints against a single latent print in about 10 minutes

LATENT PRINTS CHANCE IMPRESSIONS REQUIRE TRANSFER MEDIUM ENVIRONMENT DEPENDENT

Fingerprint Visualization At the Crime Scene Dust and Lift (powders; various colors) Magnabrush (iron filings and powder) In the Laboratory Ninhydrin for paper Superglue in tank (sometimes at scene) Other (physical developer, etc.)

NINHYDRIN EXAMPLE

AFIS HIT EXAMPLE

FINGERPRINT LAB PART TWO PART ONE TODAY C. Your Inked or pencil Prints What fingerprint patterns ? Enlarged print (at least one characteristic) D. Super Glue 1 item- glass slide PART ONE TODAY A. Black Powder 2 different surfaces: Smooth glass slide and tile B. Magnetic Powder 2 different surfaces

E. Evidence Sample Everyone will get an item to process for fingerprints using techniques you have learned/ MUST LIFT A PRINT HOWEVER!!! MUST SWAB BOTTLE FOR SALIVA FIRST (lightly moistened swab) Allow swab to dry while you work on item When dry package in envelope Once swabbed, dry the swab and then place into envelope and fill out the chain of custody Be sure to take notes on the evidence and sketch on the card.

REMINDERS MAKING A LATENT PRINT VISIBLE Place some powder in lid, not too much, circular sweeping motion, just grazing surface

REMINDERS LIFTING A LATENT PRINT ONTO A FINGERPRINT CARD Fingerprint card glossy side Don’t forget info on other side!

SOURCES Criminalistics/ Chapter 14 / Saferstein http://www.fbi.gov/hq/lab/org/lpu.htm http://www.onin.com/fp/ Kendall FG, Rehn BW. 1983. Rapid Method of Super Glue® Fuming Application for the Development of Latent Fingerprints. Journal of Forensic Science. 28(3) 777-780. Lewis, LA. et al. 2001. Processes involved in the development of latent fingerprints using the cyanoacrylate fuming method. Journal of Forensic Science. 46(2): 241-246 California Dept. Justice/ Physical Evidence bulletin-PEB 16-17 International Association of Identification (IAI)-> http://www.theiai.org