Luis' family told KHOU-TV that the father of two was killed over a $500 repair bill.
"He was a father, a son, a brother, an uncle,' sister Sandy Casillas said. "He didn't deserve this."
Witnesses allegedly saw Luis arguing with a customer before he was shot.
"My brother started running," Casillas said, KTRK reported. "He ran through all the side businesses he could run through. They did catch up to him, and they shot him in the head. [Point] blank. They put him on his knees, and they shot him in the head."