Authorities in Milford discovered bomb making materials inside a man's home on Sunday morning while responding to a report of an intruder.
Police responded to 76 Pond Street at 4:37 a.m. after a resident reported hearing voices inside and outside his house, according to police.
When police arrived, they found the resident, 28-year-old Derek Meyers, and he was holding a gun, police said, and no else in the house.
During the security check of the home, police saw what appeared to be drugs and possible explosives. They said there was a grenade-style canister in the living room and a white bucket filled with materials "consistent with explosive making materials,"
Police said they also found a clear plastic bag holding a white powdery substance, which turned out to be cocaine, a hypodermic needle, a glass pipe.
Officers left the house, secured it and evacuated nearby residents.
The State Police Bomb Squad was called to determine the potential hazards and determined that there were several hazardous materials and a homemade device that appeared to have an electronic receiver attached to remotely detonate the contents.
Police said they also found several powders and electrical components that could be used to make homemade explosives.
Investigators obtained a search warrant and found smoke bombs and smoke grenades.
One smoke grenade had been altered with a remote receiver switch and flash powder, police said.
Investigators also found potassium nitrate, ammonium nitrate, flash powder) and nitric acid.
Neighbors were allowed to return to their homes in the early afternoon.
After a medical evaluation, police took Meyers into custody.
He was charged with illegal manufacture of bombs, illegal possession of fireworks, illegal possession of explosives, possession of narcotics and possession of drug paraphernalia and is being held on $250,000.
The Connecticut Emergency Services Bomb Unit and the FBI assisted Milford Police.