DOVER, N.H. (AP) – Police seized firearms and ammunition – from an apartment complex and arrested one resident whose walls had at least 30 bullet holes.

Michael R. Steward, 19, was charged with three counts of reckless conduct, accused of shooting a .22-caliber rifle inside his apartment, and one misdemeanor charge of possessing a firearm without a serial number, police said. He was arraigned Thursday.

Firefighters responding to a smoke investigation at the complex Wednesday night found the firearms. They discovered nine rifles, a handgun, silencers, ammunition magazines and ammunition ranging in size from .22-caliber to 12-gauge.

Police also found 30 to 50 bullet holes in the walls of the apartment, a Confederate flag with a racial epithet written in black marker, a vest with four steel plates, and instructions on how to construct bombs and silencers for guns. A computer monitor had a bullet hole in the screen. There also appeared to be evidence of animal killings in the apartment, including two cats, police said.

Police had evacuated all of the 12 units inside the building.

The bomb squad was initially called to the apartment because of fears the material found inside was used to make bombs, Dover Police Chief William Fenniman said. State police later determined the material was used to make silencers for firearms.

While it is not illegal to have guns inside a residence, it is illegal to modify or alter the serial numbers on firearms. Federal law also prohibits the possession or use of silencers on weapons.