When a firearm is fired, the gun leaves a set of unique markings or impressions on the expelled bullets and casings. To date, no two firearms that leave the exact same markings have been found.
This means that every firearm essentially has its own "fingerprints." And when police compare and identify the bullets and casings they collect at crime scenes with seized guns, it can potentially provide them with the information to link those guns to other crime scenes.
"We have a saying, 'Every gun tells a story'," says Det. Chris O'Brien, a member of the Ottawa Police Service (OPS), currently seconded to the Ontario Provincial Police (OPP)'s Provincial Weapons Enforcement Unit (PWEU). "We want to know the story of that gun: who made it, who sold it, who purchased it? Those stories provide investigators with a wealth of information."
Another crime-fighting tool
To test those seized guns, police agencies use ballistics tanks. Projectiles are fired into a water-filled tank. The bullets lose their energy as soon as they touch the water and sink to the bottom and can then be retrieved and analyzed.
Ballistics testing is an important part of every gun investigation. O'Brien says every time a gun is seized and a person is charged with a firearms offence, police are legally required to prove the weapon was in working order.
Insp. Bill Klym, the officer in charge of the PWEU, adds the tests are key in successfully and efficiently solving the crimes they investigate.
"It's another tool in our toolbox," says Klym. "It might not be much on its own, but in combination with the other aspects of investigations, this information gives us further leads as to where the gun may have originated and who may have committed the crime."
Prior to purchasing their own tank, the OPS and PWEU had to send all their testing to the national forensic centre in Toronto, Ont. But the demand at the centre was so heavy that they could wait up to four months for reports they can now do the same day in-house.
When the OPS was looking into getting its own tank eight years ago, O'Brien says they were concerned about the expense of many of the models on the market. O'Brien, who was a member of OPS's Guns and Gangs Unit at the time, says the team approached a local company, Dymech Engineering Inc., to build their own.
Using items off the shelf like pool filters, Dymech worked closely with a few members from Guns and Gangs to design a tank that would meet their needs at a significantly lower cost than most of the other options.
"There's not a huge market for these out there, but our company is project based and we deal with little projects like this often," says Will Saunders from Dymech. "It was mostly figuring out what they need and they haven't been able to stump us yet."
The OPS have even had other police departments visiting, interested in building their own tanks.
Furthering criminal intelligence
Located at the OPS headquarters, the tank is used regularly by O'Brien as well as a few trained firearms examiners from the OPS. They're also working with Dymech to create an automated gun firing device for firearms examiners to use when the safety of a gun might be questionable.
The PWEU has also purchased a tank for their location in North Bay, Ont., and have funding earmarked for another two in different locations around the province.
"Ballistics is the key tool to getting to the bottom of crimes," says Klym. "In cases where a gun turns up at a crime scene, it's a dead end unless a collateral investigation is being carried out to link it to the intelligence we already have."
And O'Brien says through the testing, they've been able to link guns to different crime scenes. Even if it's not a slam dunk in a case, it provides police with greater intelligence of the criminal organizations in their jurisdiction — helping create overall safer communities.
"If I can do something to make sure guns don't fall into the wrong hands and the people that do lawfully own them are being held to a high standard, then in my mind, I'm doing a good service to the citizens of this country, province and city to make the streets safer," says O'Brien.