ANTIOCH, Tenn. (AP) — A man with "significant" psychological issues who was armed with a hatchet and pellet gun unleashed a volley of pepper spray at audience members inside a movie theater Wednesday before being fired at by a police officer and shot dead by a SWAT team as he tried to escape out a back door.

The attacker, identified as Vincente David Montano, 29, of Nashville, was carrying two backpacks, one of which hung from his chest, and he wore a surgical mask, possibly to protect himself from the pepper spray he unleashed in large amounts during the showing of "Mad Max: Fury Road," Metro Nashville Police spokesman Don Aaron said. He said three people were blasted with the spray and treated. There were eight people in the theater, including Montano, Aaron said.

As Montano fled out the back of the theater Wednesday, he encountered a SWAT team and was shot dead, Aaron said. About two dozen gunshots could be heard in a 10-second period in raw video footage posted online by WKRN TV.

Aaron said police had not uncovered a motive, but he said Montano had been committed for psychiatric treatment at least four times, twice in 2004 and twice in 2007. It wasn't immediately clear why he had been committed or if that commitment was involuntary.

"This individual has had significant psychiatric or psychological issues," Aaron said.

He also noted that Montano had been arrested in Murfreesboro, Tennessee, in 2004 for assault and resisting arrest, and said he was reported as a missing person to the Murfreesboro police department on Monday.

Police initially said that Montano had been armed with a gun and that he exchanged fire with the first responding officer, but Aaron later Wednesday identified the weapon as an airsoft pellet gun.

"The gun is a very realistic looking gun that strongly resembles a semiautomatic pistol," he said. "If someone confronted you with it, you would think it was a real pistol. Obviously an airsoft gun makes noise. When that initial officer who confronted him reported that the gun was aimed at him, the trigger was pulled, that officer heard noises. That's when the officer fired his weapon at the suspect in that initial confrontation."

The violence at the Carmike Hickory 8 complex comes about two weeks after a 59-year-old drifter opened fire inside a movie theater in Lafayette, Louisiana, fatally shooting two before killing himself. It also happened while jurors in Colorado decide whether the man who killed 12 and injured 70 others during a theater shooting in 2012 should receive the death penalty.

One of the people hit with the pepper spray in the theater also had a cut that evidently was caused by a hatchet, Aaron said. Aaron identified the victim only as Steven because he said the man did not want to bring any more attention to his family.

One of Montano's two backpacks was detonated and then found to contain a fake bomb, Aaron said. He said investigators were going through a second backpack that Montano left at the theater. No one was taken to a hospital.

The only person shot was Montano, whose motive was still unclear, Aaron said.

The entire event Wednesday transpired over less than an hour's time. Aaron said the first call came in about 1:13 p.m., and that two officers outside in the midst of a traffic stop responded within two minutes just as witnesses ran toward them. An officer came into the theater and was fired upon by the attacker, Aaron said. The officer shot back, then backed off but, Aaron said, the officer kept the gunman confined to a single theater in the complex.