CHICAGO (CBS) — Federal authorities have charged a CTA bus mechanic with making and selling homemade explosives out of his garage.

Tom Ahern, spokesman for the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives, said 34-year-old John Hegarty allegedly sold approximately 700 “flash powder” devices to an undercover agent who said he planned to blow up a car and a restaurant.

“He admitted to manufacturing them in his garage in a residential area. The inherent danger is obvious to himself and his neighbors,” Ahern said.

According to a criminal complaint filed last week, a federal informant told agents in August 2012 that Hegarty had set off some illegal explosives at a party, and sold some devices he’d made. The informant later arranged for an undercover federal agent to meet Hegarty and arrange for the purchase of some “flash powder” explosives.

Flash powder is used to make legal fireworks, as well as illegal homemade explosives.

According to the charges, Hegarty repeatedly sold illegal explosive devices to an undercover agent from August 2012 until May 2014. In most cases, Hegarty allegedly met the agent at a Metra parking lot about three blocks away from his home 6900 block of North Osceola Avenue, because he didn’t want to sell the explosives from the home he shared with his parents.

The agent used recording devices to tape his transactions with Hegarty, and paid about $7,000 for about 700 homemade explosive devices in six transactions, the complaint said.

Hegarty was arrested Wednesday on a charge of distributing an explosive device in furtherance of a federal crime of violence, according to court records. He was released on a $10,000 bond.

In at least one of the transactions, the undercover agent — who was posing as a convicted felon — told Hegarty he planned to use the explosives to blow up a former friend’s car over a drug debt. Hegarty allegedly sold the agent 150 homemade M-80s, and a “bunker buster” bomb, which was the equivalent of a stick of dynamite.

“I wouldn’t f— around with the gas tank ’cause fumes could seep out. Any of the eighties will take out a window or take off your finger,” Hegarty allegedly said. “If you really want to f— up the guy’s car, I could talk to my guy and have longer fuses made, that way you can get the f— outta town.”

When Hegarty was arrested, he admitted making the illegal explosives in his garage.

Most recently, Hegarty allegedly sold the agent more than 300 illegal explosive devices in May, including five more “bunker busters,” after the agent said he planned to blow up a Subway restaurant as part of an insurance scam.

Agents seized about 200 illegal explosive devices from Hegarty’s home when he was arrested. They also seized 14 guns and about 1,000 rounds of ammunition, along with 50 pounds of “flash powder,” according to the complaint.

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