Modern detectives use a wide range of scientific techniques and equipments ti help them identify and catch criminals.
1) Fingerprinting- Fingerprints have been used for more than 100 years to prove whether someone was at a crime scene or held a weapon. Experts dust areas for hidden prints, which can also be revealed under special lights or on contrasts.
2) DNA Testing- Now forensic scientists use DNA testing or genetic fingerprinting to prove or disapprove a suspect's connection with a crime.
3) Psychological profiling- Experts prepare profiles that suggest certain features of the killer, based on the nature of their murders. The profile may gibe likely give age, backgroud and habits.
4) Ballistics- All guns have a unique fingerprints- the marks made on bullet as it leaves the barrel. Ballistics specialists examine these with microscopes and compare bullets used in crimes with those fired from suspect's gun find out whether they are identical.
5) Surveillance- Crime fighters increasingly use electronics methods to spy on suspects. They can plant bugs( hidden microphones and video, cameras) and intercept telephone calls and computer data.
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