Criminals will find it difficult to cover their tracks now, with the Directorate of Forensic Sciences launching a project to fingerprint firearms and create a National Ballistic Imaging Database.

The Central Forensic Sciences Laboratory, Chandigarh, has begun an exercise to create a database of all guns used in crime all over the country.

Every gun leaves a unique mark on the bullet as it leaves the barrel, which is called the `firearm signature', and the CFSL will create a database of the `fingerprints' of the firearms used in crime.

"We are developing a database here with the help of bullets and cartridges already used in crimes. Once this is ready for use and its utility already established, we can approach the government to introduce fingerprinting of firearms before it is made available to the public," said Dr M S Rao, director, Directorate of Forensics Sciences.

The project is a precursor to a plan to fingerprint guns right at the level of manufacturing.

Firearm fingerprints are obtained from the bullet and the cartridge.

"We have developed a mechanism wherein we have a database of unique identity from each and every firearm used in crime. As new entries are made, the system searches the existing database, makes comparisons and helps in linking the previously unlinkable crimes committed with the same firearm in different jurisdictions," said S S Baisoya, Junior Scientific Officer (Ballistics), CFSL.

"When a gun is fired, it transfers unique characteristics or markings to the bullet and the cartridge and these are reproduced each time the gun is fired. These markings are used to confirm whether a specific gun has fired a particular bullet or cartridge case," Baisoya said.

If a firearm is recovered at the scene of crime, then a test-fire is done and test bullets and cartridges are obtained for comparison.

The crime-related bullets are compared with the test bullets.

"The bullets and cartridges recovered at one crime scene can also be compared with those recovered at another in order to link the crimes committed by the same firearm," said the ballistics expert.

Countries like the US, the UK, China, South Africa, Germany [Images], Turkey, Brazil [Images] and many more already have this system in place.

"In many countries, the firearm fingerprints are taken at the manufacturing unit by firing test bullets. Ultimately, before the firearms go to the general public and the armed forces, the database already is ready," Rao said.

He said the database will help solve firearm-related crimes, including the incidents involving terrorists, Naxalites, interstate criminals, serial killers and repeated offenders.

This database has already proven effective in many cases. "In Gujarat, we could link 16 murders. All were committed with the same firearm. In an ambush case in Tripura, examining the 214 cartridges recovered from the scene, we could figure out that 11 firearms were used," Rao said.