No one knows yet what motivated Duane Morrison to attack where he did and who he did.
"There's still no indication why he did this...why he chose that school or why he did what he did at all, " Said Lance Clem, PIO for the Colorado Department of Public Safety.
Investigators say they've examined surveillance video from the school on the day of the attack and the day before.
"There's a tape that shows the suspects jeep circling the parking lot on Tuesday...it shows him entering the parking lot on Wednesday...he stopped in the parking lot for awhile then he eventually enters the building, “ Clem says.
The tape is helping investigators piece together a timeline of Morrison's actions on the morning of the shooting...but Clem says it doesn't do much more.
"The tape is pretty limited...there is only one camera that scans the entire campus...it just scans the whole perimeter, " He says.
Another key piece of evidence...a 14-page letter Morrison sent to his brother. In it he mentions his childhood abuse, suicide and apologizes to his family, but doesn't detail what he planned to do.
"It provides no info as to why he chose the school...why he did this...it didn't detail any of that…all these pieces of evidence are going to be helpful but there's nothing that emerges as a definite explanation for why this guy did what he did, " Clem said.
Investigators say they have been unable to find any connection to victim Emily Keyes or the other hostages…although they have information that Morrison may have spent time in Bailey.