CNN) -- Throw down some drinks at The Mad Hatter bar in Orlando? Check.
Pull the fire alarm, so about 500 students in Tower 1 on the University of Central Florida campus rush outside, together? Done.
Give them hell?
Those three words were the last item of James Oliver Seevakumaran's checklist that he made before, authorities say, he would go out with up to 1,000 rounds of ammunition and start shooting, possibly setting off bombs in the process.
It was not crossed off.
Instead of a mass killing early Monday morning, police reported only one fatality: Seevakumaran.
Video released a day later by University of Central Florida police shows the moment officers discovered him. After getting into his suite, they unlocked his room's door and barged in, yelling and with their weapons raised.
It didn't take them long to realize there was no threat. The 30-year-old lay prone on the floor, having killed himself with a handgun.
"All indications are, just like the rest of his life, he was alone," UCF police Chief Richard Beary said Tuesday.
After just more than a day of investigating, authorities have been able to piece together much of what happened. They have seen surveillance video that shows Seevakumaran pulling the alarm, then returning to his room. They recovered weapons and ammunition as well as four homemade bombs and the checklist. They interviewed many who described him as a loner who didn't like to talk to others but wasn't viewed as a threat.
What they don't know is why he did what he did.
"There's no manifesto, there's no documentation," Beary said. "... We have not uncovered anything that would give us a motive or a rationale."
Family calls him 'a loner'
The statement issued Tuesday by Seevakumaran's family, initially to the Sarasota County, Florida, sheriff's office, didn't shed much light on his thinking.
"The family of James Oliver Seevakumaran states that James was a loner and did not have a history of violence," they said.
From fall 2010 through fall 2012, he had been a UCF student. But he was not enrolled for the spring semester, and was in the process of being removed from the dorm room where he lived, school spokesman Grant Heston said.
According to Heston, Seevakumaran was never seen by UCF counselors and had not had any student conduct issues. He had one prior contact with law enforcement -- a traffic arrest in 2006 -- the police chief said.
One of his roommates talked with a reporter from the Knightly News, a UCF student news organization. He said Seevakumaran would seemingly make an effort to avoid walking near him, that he wouldn't say anything back when you said hello.
"The only time that he made solid eye contact with me was when he was pulling the gun on me," the roommate said.
That happened as lights were flashing and the alarm was ringing around 12:20 a.m. Monday, inside their suite. Unsure if he could make it to the hallway, Seevakumaran's roommate bolted to his room.
"I slammed the door on him before he could pop anything off," the roommate said, recalling how he moved away from the door and hid behind a chest of drawers.
While realizing Seevakumaran was far from a rah-rah college student, the roommate didn't consider him a threat.
"I just thought that he kept to himself a lot," he said, according to audio posted on the Knightly News website. "I just thought he was a quiet, introverted person."
'I don't think you do that as a joke'
Whatever his relatives and acquaintances thought of him, police said they believe that Seevakumaran had devious plans of his own.
Waiting for him in the university mail room were two 22-round magazines for his semi-automatic rifle, a sling for that weapon, and a training DVD on how to use its laser and shoot it, authorities discovered Tuesday.
This is in addition to the ample ammunition -- including drum magazines, one of them found attached to the gun, that can contain 110 bullets each -- that authorities have found. Then there were the bombs, which Beary said he believes Seevakumaran made himself
Seevakumaran likely spent about $1,000 to buy the guns and ammunition in February, suggesting his plan was set in motion as early as then, the police chief said.
Of course, there also was the checklist he'd drawn up -- and largely followed, albeit apparently hours later than he had planned, after scribbling out items such as "get drunk" and "take shower" -- ahead of his death.
"I don't think ... you purchase 1,000 rounds of ammunition" without a plan, Beary said. "I don't think you do that as a joke."
While Seevakumaran is the only one dead, the mere possibility that he would wage an attack has already had an impact.
Dorms were evacuated, classes were canceled, and the UCF campus was shut down. Counselors were in Tower 1 and elsewhere to talk with students coming to grips with the drama.
School authorities couldn't promise that something like this wouldn't happen again, but they did send out more police on patrol to help students feel safe.
"All of us have a role
to play in the welfare of our campus," school President John C. Hitt said Tuesday in a statement, "and we will work together to use this experience to make us even more prepared, more alert, and more secure.
CNN's John Couwels, Dana Ford and Marlena Baldacci also contributed to this report.
(AP) The 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.
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 victims. Beary says the final item was "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.
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 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.
The roommate who called 911 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 who called 911. 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.
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 morning classes were canceled at the 51,000-student campus.