A 48-year-old man arrested Sunday night at a Thornton movie theater for wearing a holstered weapon said he was simply exercising his right to bear arms.

“I was a threat to no one. I didn’t threaten anybody,” said James G. Mapes, who was taken into custody after carrying a handgun into the Cinebarre movie theater at 1001 Grant St.

In an interview Monday morning, Mapes said he has a concealed-weapon permit issued in 2003 by the Arapahoe County Sheriff’s Office. Since he got the permit, he said, he has carried a handgun frequently, including on trips to grocery stores.

“I’ve had no problems in the past,” Mapes said. “I’ve never had police take my gun from me in the nine years I’ve had the permit.”

But Sunday night, nine days after 12 were killed and 58 injured in an Aurora theater shooting, was different. Someone called Thornton police to report that Mapes was in a movie theater with a sidearm.

Officers responded, and several auditoriums were evacuated as a precautionary measure.

“The subject’s possession of the firearm caused alarm to the theater staff and fellow movie patrons,” police said in a media release.

Mapes, who lives in Northglenn, was in a darkened theater, he said, about 15 minutes into viewing “The Watch,” when the lights came on and the show stopped. He said a woman sitting nearby took a cellphone call and then said aloud that someone in the movie complex was seen carrying a gun.

“That’s probably me,” Mapes recalled responding.

He said he got up from his seat and headed out of the theater when he heard officers in the lobby giving commands to movie patrons.

“I walked out there and just put my hands out” away from the holstered weapon, Mapes said.

Mapes was disarmed, handcuffed and arrested.

He was booked on suspicion of “possession of a dangerous weapon,” in violation of municipal ordinance 38-237, police said.

Mapes was issued a summons and released.

Investigators confiscated the gun as evidence.

“This case is under review by our city prosecutor,” Thornton police spokesman Matt Barnes said.

“We are an open-carry state,” Barnes said. “We look at the open-carry law and how it relates to this incident. He felt he was exercising his right to bear arms in an open-carry state, and we are currently reviewing that with our prosecutors.”

Kieran Nicholson: 303-954-1822, knicholson@denverpost.com or twitter.com/kierannicholson