A U.S. District judge sentenced an Amado man last week to six years in prison for planting explosive devices in 2017 that injured one person, according to authorities.

Constantino Varela, 64, pleaded guilty in August 2018 to two counts of unlawful possession of an unregistered destructive device and one count of possession of firearms by a convicted felon, according to a press release from the U.S. District Attorney's Office.

Varela, suspecting vandals were breaking into a building on the property where he lived, built an explosive device containing metal balls and nails and planted it on the property, the press release said. The device was connected to a pressure switch mounted on the floor near the building's entrance.

Read more: Arizona Daily Star