Catching criminals has become quite a defined science with the latest in technological advances and modern methods of crime investigation. In today's society, perpetrators are identified through various updated body fluid tests, by examining suspects' computer hard drives, and through DNA analysis, Fingerprints of known criminals can be identified in minutes through automated fingerprint identification systems. Even popular TV shows like "Criminal Minds" give us some insight as to how criminal profilers work.
In today's society, most people have at least one computer in their home, and that has become another forensic tool for investigating crimes and catching perpetrators. A computer trail can be likened to leaving digital footprints in a sense. Child pornography rings can be located through people's use of Internet sites, for example, and examining a person's hard drive can uncover other evidence to crack a case. In murder investigations where premeditation is suspected, the forensic team may find evidence of searches on how to kill people or on poisons, or they may find incriminating e-mail communication that helps to convict a suspect.
Automated fingerprint identification system
It is much easier to identify fingerprints left at crime scenes in modern times thanks to the automated fingerprint identification system, also known as AFIS. In the past, suspects were fingerprinted using black ink. The updated method involves rolling fingers and palms of suspects onto a glass plate on a scan terminal. An identification technician sends the print images to the AFIS to be compared with over five million fingerprints in a database. The AFIS identifies any matches to a person that was previously arrested or someone who has a warrant out on them within a matter of minutes.
Modern body fluid tests
A variety of tests are used in cases of sexual assault and homicide to identify body fluids at the scene of a crime. Body fluids include saliva, semen and blood. Forensic technicians test for semen using acid phosphatase. When this enzyme is applied to semen, it will turn a purple colour. Blood is identified by applying the "Kastle-Meyer" test. This involves using phenolphthalein, which is clear but turns pink when blood is detected. Another modern blood detection chemical is luminol. Crime investigators will spray luminol around a room and then turn the lights off. Even tiny droplets of blood will be revealed. To test for the presence of saliva, technicians use the Phadebas Amylase test. When saliva is present on an article of clothing or bedding, a blue dye is released due to the amylase being present.
One of major updates in criminal investigation methods is the use of DNA analysis. Since the late 1980s, advances involving DNA technology have helped to convict criminals and eliminate innocent suspects from suspicion. DNA analysis is used on skin tissue, blood, saliva, semen and hair and is now considered a reliable tool in linking criminals to crimes they committed. DNA analysis is used today by defence lawyers, prosecutors, police and courts in North America.