Crime Detection Techniques and Tools

To a catch a criminal, a range of scientific techniques are used to establish an identity and process evidence. Even what seems like a flawless plan can leave behind an incriminating fiber, drop of blood or piece of hair. When this happens, forensics can piece together the clues that identify motive and possible suspects. In this article, you will learn about the different techniques and tools that the police use to catch the bad guys.

Fingerprinting

Fingerprints are a unique piece of identification for every person , as no one has the same fingerprint , not even identical twins. The prints that people leave behind have been used for more than 100 years to prove if someone was at a crime scene or if they had held a specific weapon in their hands. When a crime is committed, one of the first things that are done is a dusting for fingerprints. They will concentrate on prints found on dead bodies, murder weapons, drinking glasses, doorknobs, windows, and other objects. Even if a faint print is found, authorities can use laser image enhancement to create a clearer picture.
DNA Testing

For the criminal that likes to pin his wrongdoing on others, DNA testing allows forensic scientists to prove or disprove that a suspect is connected to a certain crime. Everyone possesses unique DNA just as they do fingerprints. Even the smallest of samples can point the police in the right direction. It could be a single strand of hair or a drop of saliva. Researchers can learn a lot about a person with these items.

The first reports of DNA profiling came in 1984 when Sir Alec Jeffreys worked at the University of Leicester in England. What he documented would lead to the foundation of several national DNA databases. It wasn’t until 1987 that Jeffrey’s genetic fingerprinting was a commercial technique that the public could use. A chemical company called Imperial Chemical Industries (or ICI) established a blood-testing center in England.

A couple of cases where DNA testing played a significant role include:

During the 1950s, Anna Anderson claimed to have been Grand Duchess Anastasia Nikolaevna of Russia. After her death in the 1980s, samples of her tissue that had been stored at a hospital after a past medical procedure were tested using DNA fingerprinting. They revealed that she was not related to the Romanovs.

The first person in the United States to be convicted as a result of DNA evidence was Tommy Lee Andrews , a rapist from Florida. He had raped a woman during a burglary and was convicted in 1987 and given 22 years in prison.

Ballistics

Every gun is made with their own unique ‘fingerprint’, which are the marks made on a bullet when it leave the barrel of the weapon. Specialists are trained in the study of ballistics to compare bullets that have been used in a crime by looking under a microscope. They use the markings on a bullet to learn about the associated weapon. When an identical match is found, it tells investigators more about the person who may have fired the weapon.