Once evidence is collected, it must be developed and examined using various types of equipment and chemicals.
Fingerprints-developed and examined using the contrast method, and fuming methods, comparison to known prints, and fingerprint microscopes.
Firearms and tool striations- developed and examined using morphology, spectrophotometers, mass spectrographs, and various magnifying instruments
Trace Evidence- developed and examined using tapes, filters, spectrometers, high resolution lenses, various microscopes, spectrographs, x-ray diffraction, neutron activation, and chromatography instruments
Document Evidence is developed and examined in numerous ways, by experts in forgery, handwriting, fingerprints, paper, and ink, using fuming, microscopes, magnifiers, chemicals, spectrometers, chromatographs, and spectrophotometers
Testimonial evidence is examined with polygraph tests, voice analysis, body language, and the skills developed by the investigator.
Fingerprints- can definitively identify a suspect, and place them at the scene of the crime because no two people have the same fingerprint whirls, arches, loops, dots, ridge endings, bifurcations, short ridges, enclosures, bridges, spurs, or trifurcation ridge endings
Firearms, shoes, and tools develop individualized striations from use or manufacture that can positively identify them as being at the scene, or help to reconstruct the scene using morphology
The rules of Locard's Law applies to everyone, not just suspects, victims and witnesses
Environmental issues such as rain, heat, wind can contaminate or cause the evidence to erode, deteriorate, or disappear
For witness corroboration, people can forget details
Too many people in the crime scene area
Improper packaging or storage
Tamper Resistant Evidence Bag
Relevant Issues The sciences of evidence have come a long way in a few short years. While there are still issues concerning the reliability of the science behind the results, the advanced use of science has proved to be an invaluable tool in the protection of those who are innocent Wheel used to mark off crime scene