COLUMBUS, Ohio (WCMH) — A 20-year-old Columbus man pleaded guilty Friday to assaulting and robbing two mail carriers.

Brandon J. Campbell admitted to assaulting two mail carriers — once on Sept. 8 and again on Sept. 21 — by brandishing a Glock-style handgun to steal keys used to open USPS mailboxes and receptacles, according to a Friday news release from the U.S. Attorney’s Office for the Southern District of Ohio.

The first robbery occurred at Vistas at Rocky Fork Apartment Complex in Gahanna, and the second took place near 4500 Hemingway Court in Columbus, the release said.

After executing search warrants, investigators discovered four firearms in Campbell’s apartment and a balaclava mask he wore during the robberies, according to the release. Data obtained from Campbell’s phone revealed a photo of Campbell holding a Glock-style firearm.

If convicted, Campbell faces up to 25 years in prison for aggravated robbery, according to the U.S. Attorney’s Office.