INDIANAPOLIS -- Indianapolis police and the FBI are investigating a series of break-ins on the city's northwest side early Thursday morning that resulted in several dangerous weapons in the hands of thieves.

One of the victims is a FBI SWAT agent, who had a .45-caliber semiautomatic handgun, MP5 submachine gun, LAR-15 semiautomatic rifle and two sets of body armor stolen from his vehicle, police said.

Thieves hit at least 12 homes, breaking into garages and vehicles in the Normandy Farms and Lakeside neighborhoods, west of Interstate 465 between 71st and 86th streets, in the early-morning hours, police said.

Investigators said other weapons, including a shotgun, were taken from other homes and vehicles. The thieves also got a sheriff's deputy's badge and a Harley-Davidson motorcycle from other homes.

"It's crazy to know that you live in such a nice neighborhood and those kinds of things can happen to you," one resident said.

Police said the agent had followed proper protocol for storing weapons in a vehicle. The guns were in a chained lockbox in the trunk, but that didn't deter the thieves, 6News' Jack Rinehart reported.

FBI officials, worried that the guns had fallen into the wrong hands, are working with Indianapolis police to take DNA swabs and use other methods of evidence collection in hopes of catching the thieves.

"Those weapons are going to be hard to get rid of," said Indianapolis police Sgt. Paul Thompson. "Those individuals who have them now probably know that ... because they're unique."

Nearby residents said that thefts are not common in the neighborhood, but that they will be more vigilant.

"I think they'll get a real welcoming committee if they try that in our house," one man said. "We'll be ready for them."