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.
The list 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 potential victims. A photo of the list shows the final item reads: "good luck & give them hell!"
Instead, Seevakumaran shot and killed himself as police officers arrived in response to the fire alarm and a 911 call from a roommate. Beary says authorities confirmed he had gone earlier to the bar and drank. No one else was hurt.
In the 911 call made public Tuesday, Arabo "BK" Babakhani spoke in a calm but urgent tone as the screeching of the fire alarm made it difficult for the dispatcher to him. He said he had opened the door to his room because of the fire alarm and saw Seevakumaran with a gun.
"He pulled a gun on me," Babakhani said. "The fire alarm went off. I opened the door to see what's going on and he's there with some gun.
Babakhani told the dispatcher that he slammed shut his door and locked it.
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 four makeshift explosives in a backpack, an assault rifle, handgun, high capacity ammunition drums and hundreds of bullets near his body.
The police released a video of officers' response to the scene that shows several of them cautiously entering the suite with their guns drawn as strobes from the fire alarm flash. The footage shows them entering the room and discovering 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 they haven't found a written explanation.
More details emerged Tuesday about Seevakumaran's solitary lifestyle. 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.
Babkhani said Seevakumaran rarely left the dorm apartment, according to a dispatcher's notes.
In an interview with student publication Knightly News, 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.
Freshman 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.
The business major, who held a job at an on-campus sushi restaurant, had never been seen by university counselors 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. He had attended the university from 2010 through the fall semester.
Some 500 students were evacuated from the dorm just after midnight Monday, and classes that morning were canceled at the 51,000-student campus.