GLOUCESTER CITY, N.J. (AP) — Authorities say a New Jersey man is facing federal charges in connection with a homemade explosive device detonated at the entrance of a local gym last month. Gloucester City police said officers were called shortly before 4 a.m. on Aug. 26 to Bellum Strength and Conditioning and found the entrance damaged by the blast.

Police said, after an investigation aided by Camden County prosecutors and the FBI, 35-year-old Dwayne Vandergrift Jr. was arrested two days later. Police said residences on his block were evacuated for a time until the home was deemed safe.

The U.S. attorney’s office said Friday that Vandergrift was charged with malicious use of explosives, unlawful possession of two destructive devices, and a firearms charge.

Authorities said security camera footage showed the defendant fleeing the area moments before the device exploded, badly damaging the front door and shattering glass at the gym.

Investigators allege that “substantial quantities” of bomb-making materials were found in the defendant’s home and a search of his computer revealed research on how to build and use explosive devices such as pipe and pressure cooker bombs.

Vandergrift remained in custody in the county jail; it’s unclear whether he has an attorney and a listed number in his name was out of service Sunday.

(Copyright 2020 by The Associated Press. All Rights Reserved.)