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Developing Prints bsapp.com.

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Presentation on theme: "Developing Prints bsapp.com."— Presentation transcript:

1 Developing Prints bsapp.com

2 Fingerprints Visible prints (contaminated) are made after coming in contact with colored material such as blood, paint, grease, or ink. Plastic prints are ridge impressions left on a soft material such as putty, wax, soap, or dust. bsapp.com

3 Fingerprints Latent prints (invisible prints) are impressions caused by the transfer of body perspiration or oils present on the finger to the surface of an object. Latent prints must be developed or made visible bsapp.com

4 bsapp.com bsapp.com

5 Dusting Appropriate Surface:
Ridged/non-porous such as glass, plastic, or metal Theory: Dust will adhere to sweat & oils left behind bsapp.com

6 Cover Surface With Dust
bsapp.com

7 Remove Excess Dust Brush or Blow bsapp.com

8 Use Tape to Lift the Print
bsapp.com

9 Place Print on a Card bsapp.com

10 Iodine Fuming Appropriate Surface:
porous and non-porous such as paper, index cards, magazines, and cardboard. Theory: Sweat and oil will absorb iodine vapors bsapp.com

11 Place the Object in an Enclosed Container with Iodine Crystals
bsapp.com

12 Print Should Develop in a Few Minutes
bsapp.com

13 Ninhydrin Appropriate Surface:
porous such as paper, tissue, cardboard,currency & clothing Theory: ninhydrin reacts with amino acids to form a purple compound bsapp.com

14 Soak Suspected Surface with Ninhydrin Solution & Allow to Dry
bsapp.com

15 Print Should Develop Within 24 Hours
bsapp.com

16 Cyanoacrylate Appropriate surfaces: non-porous surfaces such as plastic, metals, glass, enamel and varnished wood surfaces. Theory: Cyanoacrylate emits a vapor that reacts with trace amounts of moisture plus organic compounds that have bonded to the surface.

17 Fingerprint produced

18 Silver Nitrate & UV-Light
Appropriate Surface: porous such as paper or drywall Theory: When exposed to ultra-violet (UV) light, silver nitrate reacts with the salt in sweat to form a blackish-brown compound bsapp.com

19 Spray Surface With Silver Nitrate Solution
bsapp.com

20 Expose to UV-Light bsapp.com

21 Print Should Develop in 5-10 Minutes
bsapp.com

22 Other Methods In recent years, there has been much advancement in the area of print developing. Advanced brushes and new chemical procedures make it possible to develop prints on a larger variety of surfaces. There are over a hundred different methods used to develop fingerprints, depending on the surface being examined bsapp.com

23 Latent Fingerprints from human Skin
Attempts to lift prints should be made with in 11/2 to 2 hours Its best to lift prints at the scene if possible Many techniques can be used to lift brints off skin.

24 Dusted fingerprint on skin

25 AFIS Integrated Automated Fingerprint Identification System
Contains fingerprints and corresponding criminal history for more than 47 million subjects Housed at the FBI


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