Timothy Gallagher, 21, was found in an alley in the 400-block of W. Fullerton Sunday morning. He had suffered head trauma.
His father, Jim Gallagher, wants to know why his son was there and how he died.
Jim Gallagher says Tim was seen less than an hour before -- getting out of a cab and going into a building at that location.
It is unclear why he was there.
Gallagher had been out with friends, but they became separated.
"I need those answers. There's never going to be full closure on this for any family members i understand that... but also i don't want to go through life wondering."
Jim Gallagher says his son was upbeat, loved to fish and had a ton of friends.