A girl leaves flowers Friday at a memorial in Lafayette, La., dedicated to victim Jillian Johnson who was killed in a shooting at the The Grand 16 theater there. Police said a 59-year-old man stood up about 20 minutes into Thursday night's showing of “Trainwreck” and fired on the audience with a semi-automatic handgun. Two women died in the attack.

LAFAYETTE, La. — Emily Mann and her friend had come into the theater a bit late for the evening showing of “Trainwreck” so they quietly found seats near the top of the small theater. The 21-year-old didn’t notice the man just a few seats down until 20 minutes into the movie when he got up and began firing into the crowd.

“You hear one loud shot and you’re sure that’s not what it is because it would never be that. And then you hear another and another and another and you realize that those aren’t just lights and sounds,” said Mann, speaking to The Associated Press about the brutal killing in a Lafayette movie theater Thursday evening.

John Russell Houser, 59, stood up without a word and started shooting, leaving a horrific scene of blood, bullet holes, spent shell casings, and personal possessions like purses and wallets in a movie theater that was supposed to be a refuge from the stress of daily life.

Amid the tragedy, a tale of heroism emerged: high school English teacher Ali Martin, suffering from a gunshot to the kneecap, made her way to a fire alarm and pulled it. Police say she saved lives, alerting some 300 people in the giant multiplex that something wasn’t right.

Police say Houser then tried to blend into the crowd heading outside as the alarm blared. But he turned back as police officers approached, reloading and firing into the crowd before killing himself with a single shot inside the theater, police said.

“This is such a senseless, tragic action,” Lafayette Police Chief Jim Craft said. “Why would you come here and do something like this?” Investigators recovered Houser’s journals, were studying his online postings and trying to reconstruct his movements to identify a motive and provide what Louisiana State Police. Col. Michael Edmonson called “some closure” for the victims’ families.

Craft said Houser bought the weapon legally at a pawnshop in Phenix City, Alabama, last year, and that he had visited the theater more than once, perhaps to determine “whether there was anything that could be a soft target for him.”

He had only been in Louisiana since early July, staying in a Motel 6 room littered with wigs and disguises. His only known connection to Lafayette was an uncle who died there three decades ago.

Details quickly emerged about Houser’s mental problems, prompting authorities in Louisiana and Alabama to bemoan the underfunding of mental health services in America.

Court records describe erratic behavior and threats of violence that led to a brief involuntary hospitalization in 2008 and a restraining order preventing Houser from approaching family members. Houser “has a history of mental health issues, i.e., manic depression and/or bi-polar disorder,” his estranged wife told the judge.