The van is in a testing phase right now and may only be around for the summer.
"They have been here in the city of Chicago that van for the last three weeks we have them for another month. I would hope that the ATF would keep the resources here in the city of Chicago throughout the summer in helping our police department," said Mayor Rahm Emanuel.
It's called the NIBIN (National Integrated Ballistic Information Network) van. It comes with an attachment which allows investigators to test fire weapons found at a crime scenes and examine shell casings.
"Each casing is like a fingerprint and so we're able to associate those cartridges with other shootings so that will help us track down these guys a lot quicker," Superintendent Eddie Johnson said.
So a process which could take days would only take hours. The van was first tested in Baltimore, a city struggling with gun violence like Chicago.
"Unfortunately in the first weekend, the gun violence generated cartridges which gave them more evidence than they had found in the previous month in the city of Baltimore," said U.S. Senator Dick Durbin. "It is definitely necessary."
The ATF says it has been successful so far in Chicago being able to trace bullets or guns to different crimes to generate more leads and more vans are in high demand.
"This is the only one we have currently. We also have one that's in the process of being completed we're hopeful that within the next fiscal year we'll be able to provide several others to our fleet," ATF Special Agent David Coulson said.
Supt. Johnson said they requested the van and the ATF answered the call. The ATF is focusing on cities with the biggest problems first.