Dayton police believe an argument inside the hall spilled into the parking lot where Tillman was shot.
A friend drove him to a hospital where he was pronounced dead.
His death remains unsolved.
Tilman's family said they are offering a $5,000 reward leading to an arrest and conviction in the case.
Teresa Marshall, the victim's mother, said, "All this violence needs to stop. It just needs to stop period. No mother should have to go through this. No mother. You never would think, never would think, never would think."
Tilman's father, Marcus Tillman, said, "And I don't know what really happened and I'm trying to find out what happened."
If you have any information about the shooting of Tillman, contact Dayton police at 333-COPS.
Marcia.Ehlers@WHIOTV.com