ST. LOUIS – A Jefferson County man appeared in federal court Tuesday and admitted building and possessing a pipe bomb in the summer of 2023.

Prosecutors with the U.S. Attorney’s Office with the Eastern District of Missouri said Robert Hiler, 38, pleaded guilty to one count of possession of an unregistered destructive device.

On Sept. 11, 2023, deputies with the Jefferson County Sheriff’s Office went to Hiler’s home with a court-approved warrant to look for another man who had active arrest warrants. Deputies located and arrested that individual behind Hiler’s home.

Hiler then gave deputies consent to search his home, where they found a pipe bomb in a grey bucket in a room next to the garage.

Hiler told that court that he’d planned to ignite the bomb using a car battery. A statement from federal prosecutors did not elaborate further on Hiler’s plans.

Hiler will be sentenced in July. He faces up to 20 years in federal prison as well as a $250,000 fine.