Investigators so far have spent more than 3,000 total hours conducting 156 interviews and gathering more than 223 leads to unravel what might have motivated the suspect, 21-year-old Ahmad Alissa, to travel from Arvada to Boulder to open fire on shoppers and workers in the middle of a Monday afternoon.

“Like the rest of the community, we too want to know why. Why that King Soopers, why Boulder, why Monday?” Boulder Police Chief Maris Herold said at a news conference Friday morning. “Unfortunately, at this time, we still don’t have those answers.”