AUGUSTA — A city man was arrested Thursday on a charge of criminal use of explosives as authorities searched his Gage Street apartment and later detonated explosive material allegedly found inside.

The man, Jeremy Upp, 36, of 42 Gage St., was taken to the Kennebec County jail, where he remained held on $25,000 bail Thursday night.

Joseph Thomas, acting state fire marshal, said his office executed a search warrant on Upp’s apartment at 12:45 p.m. Earlier, Sgt. Ken Grimes of the State Fire Marshal’s Office said they were looking for “potential energetic materials,” meaning explosive or detonating-type items.

The response came after Upp’s probation officer expressed concern illegal activity may be going on, Thomas said. According to records, Upp has a criminal history in Florida and Washington for charges including domestic-violence assault and possession of cannabis.

The Maine State Police Bomb Squad detonated unidentified material Thomas said was found in an occupant area of Upp’s unit after 7 p.m. Thursday.

Neighbors from homes next to Upp’s were evacuated when the material was detonated. Occupants watched the scene from across from Upp’s home on Gage Street. More gathered in the parking lot of Penney Memorial United Baptist Church off Memorial Drive, behind the house not far from the backyard.

Thomas said from what he knows about the material found, virtually anyone has access to it.

“A lot of this stuff isn’t in and of itself dangerous,” he said, “but when you get on the Internet and start learning how to mix it together, that’s when it becomes dangerous.”

Upp’s live-in girlfriend, Amanda Bechard, said the materials were purchased at Pyro City Fireworks in Manchester and weren’t inherently dangerous.

“I gave it to them right when they got here,” she said. “$25,000 bail? This is not that serious. You know what it is? They have nothing better to do.”

When asked about the quantity of material found, Thomas said simply that there was “enough in there to be concerned, so they rendered it safe out back.”

Near the scene, neighbors said they have been hearing loud explosions in Upp’s backyard for extended periods of time. Some said a month; some said a few days.

John Westberg, who lives nearby on Water Street, said he first heard booms from the area over the past week. At times, they would occur every couple of hours irregularly, he said.

Pam Plourde, who lives across the street from Upp, said she first called police about a month ago and they couldn’t find anything related to blasts.

“With all the stuff that goes on in these two buildings, I thought it was a rifle and someone was getting shot,” she said. “I used to like to come sit on my deck out there at nighttime, but I haven’t dared to because I didn’t know what the hell was going on over here.”

Richard Shaw, who lives in a unit next to Upp and Bechard, said the pair were pleasant but often fought loudly.

“That’s how they communicate,” he said. “They told me that when they first moved in.”

Many of the neighbors stood and watched the proceedings all afternoon, and most expressed relief at Upp’s arrest.

“It seems like we’re getting well protected,” said Tina Jaquith, another neighbor.

Michael Shepherd — 621-5632

mshepherd@mainetoday.com