Updated: Friday, 15 Oct 2010, 5:07 PM CDT
Published : Thursday, 14 Oct 2010, 3:21 PM CDT
AUSTIN (KXAN) - University of Texas gunman Colton Tooley visited websites dealing with depression leading up to the late-September shooting, though his motive for it all remains unclear.
The 19-year-old walked onto the campus in a black suit and mask , firing off rounds from an AK-47 on Sept. 28 before then killing himself inside the Perry-Castaneda Library .
UT Police Department Chief Robert Dahlstrom said the investigation has wrapped up, left with the looming question as to why it happened in the first place.
Dahlstrom said there's a chance they will never know why the sophomore math major took his life in such a high-profile way, with an AK-47 bought by his father.
During a press conference Thursday, the chief said Tooley rode a Capital Metro bus to campus that morning with the gun hidden in a backpack. Once he got off the bus, he threw away a laptop - which police later found - and changed into a black suit.
That laptop led investigators to evidence that the troubled teen had visited websites dealing with depression.
Throughout the investigation, no suicide note was ever found. And UT police said they don't know why the student chose the sixth floor of the PCL as his final destination - other than the fact that he visited that floor often.
"Hopefully, we can bring closure to this and move on and move forward and hope and pray this never happens again anywhere in Austin, Texas," said Dahlstrom.
The chief expressed his pleasure with the way his officers and the university community reacted to the shooting. He said everyone learned from this shooting and that he is fortunate it wasn't worse.
Dahlstrom added Tooley's parents have been extremely cooperative throughout the investigation.