A Massachusetts teen was arrested Friday for allegedly stealing two high-powered rifles from an FBI SWAT emergency team vehicle parked outside of an agent's home.

The bureau's Boston division announced Wednesday that $20,000 would be rewarded to anyone who could provide information leading to the recovery of the Colt M16-A1 Rifle and HS Precision Pro-Series 2000 Sniper Rifle, both of which were nabbed from the car sometime that night or Thursday early morning. The Boston Globe reported that the FBI didn't specify who the weapons belonged to, but did say that the vehicle was parked in a residential neighborhood in Andover with no connection to any investigation or sting.

Less than two days after the rifles were snatched, police told Reuters they'd identified the culprit, and the guns were returned to the agent to whom they belonged.

"The guys have been returned and an arrest has been made," said on Andover law enforcement  official who spoke on conditions of anonymity. He did not specify further details.

Chief counsel for the Boston FBI's office Damon Katz said that authorities were also in the midst of an investigation into the theft to find out whether the owner of the weapons properly stored them in the vehicle. Katz told the Globe that some agents are permitted to keep their firearms in vehicles under certain circumstances and rules.

"It is allowed with proper authorization and following proper methodology, so it's a case-by-case basis," Katz stated.

According to a bid drafted by the Boston Police Department on assault rifle storage policies, arms should be kept in a locker designated for guns in the district station. In a vehicle, the gun should be held in a locked container, and the officer should make sure that no outside parties can get a hold of it.