ORLANDO, Fla. – A former student behind an aborted attack plot at a Florida university was working off a checklist that included plans to get drunk, pull a fire alarm and then “give them hell,” authorities said Tuesday.

James Oliver Seevakumaran was crossing items off his list ahead of his planned attack on classmates with guns and homemade explosives, University of Central Florida Police Chief Richard Beary said at a news conference.

Seevakumaran shot and killed himself as police officers arrived in response to the fire alarm and a call to emergency dispatchers from a roommate.

The checklist found along with his dead body early Monday included drinking at a bar near campus and pulling the fire alarm — which investigators believe was meant to flush out victims. Beary said the final item was “give them hell.”

He said authorities confirmed Seevakumaran had gone earlier to the bar and drank.

At the time of the attack, packages were waiting for Seevakumaran at a campus mailroom containing two 22-round magazines and a sling for his rifle and a firearms training DVD, officials said Tuesday.

Investigators have also said that they found an assault rifle, handgun, high capacity ammunition drums, hundreds of bullets and four makeshift explosives in a backpack near his body.

Beary said authorities still aren’t aware of a motive or significant circumstance that led Seevakumaran to plan for an attack. The chief said no written explanation was left.

More details emerged Tuesday about the solitary lifestyle of the business major, who attended the university from 2010 through the fall semester but hadn’t enrolled for the current semester. The school had been in the process of removing him from the dormitory.

Seevakumaran’s family said he was a loner who didn’t have a history of violence in a brief statement released by authorities. Beary told the news conference that he acted alone and didn’t have any friends.

“He didn’t like to talk to people,” Beary said.

The roommate who called authorities said Seevakumaran rarely left the dorm apartment, according to a dispatcher’s notes. The caller also said Seevakumaran had pulled a gun on him.

In an interview with student publication Knightly News, Arabo “BK” Babakhani identified himself as the roommate. He said he slammed the door on Seevakumaran after seeing the gun and hid behind furniture.

Babakhani said Seevakumaran avoided eye contact, never had visitors to the dorm and never was seen talking to anyone on a cellphone.

“Instead of walking by me, sometimes he’ll walk around me,” the roommate said in an interview posted on the Knightly News website. “The only time he made solid eye contact with me is when he was pointing the gun at me.”

Babakhani didn’t immediately respond to messages left by The Associated Press.

AP reporters have also knocked on the doors of his mother and sister’s homes, but no one answered.

Mechanical engineer student Spencer Renfrow said when he would see Seevakumaran in the dorm’s hallways and elevator, he would wave and Seevakumaran would wave back.

“Everything would seem fine,” Renfrow said.

Seevakumaran, who held a job at an on-campus sushi restaurant, had never been seen by university counsellors and had no disciplinary problems with other students, said university spokesman Grant Heston. Heston said that the school had been in the process of removing Seevakumaran from the dormitory because he hadn’t enrolled for the current semester.

Some 500 students were evacuated from the dorm just after midnight Monday, and morning classes were cancelled at the 51,000-student campus.