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FORENSIC SCIENCE Unit 2B Day Four. What are the types of chemical lifts?. Iodine fuming: iodine crystals are heated, sublimate Adheres to the starch particles present in print Results in bluish-black color. Chemical lifts continued. Cyanoacrylate fingerprints: Superglue
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What are the types of chemical lifts? • Iodine fuming: iodine crystals are heated, sublimate • Adheres to the starch particles present in print • Results in bluish-black color
Chemical lifts continued • Cyanoacrylate fingerprints: Superglue • Works best on nonporous surfaces • Glue sublimates and adheres to fingerprints • No one has conclusively determined why it works
Chemical Lifts continued • Ninhydrin: chemical reaction occurs between amino acids present in perspiration • Results in purple-blue color • Ninhydrin reacts with any protein, so don’t get it on your skin!
Chemical lifts continued • Silver Nitrate: sometimes the only method that works with older prints • Chloride ion in perspiration reacts to form silver chloride • Transformed by UV light into silver • Print shows up as black or reddish-brown
Today’s Assignments AKA Justin Anderson is #1 • Due Today: Fingerprint Basics webquest and Fingerprint Flipbook • Chemical lifts- set up superglue print, complete iodine print and OMIT Silver nitrate print: TABLE 4 • Fingerprint powder one-pager activity: FRONT TABLE
Journal 4 • Calculate the primary identification number for someone with the following print types. • Pinky fingers: right- arch; left- arch • Middle fingers: right- whirl; left- loop • Thumbs: right- whirl; left- whirl • Ring fingers: right- arch; left- loop • Index fingers: right- loop; left-loop