HOUSTON – A masked man in a wheelchair rolled up behind a man and shot him Sunday outside a gym in midtown Houston, police said.

The shooting was reported around 1 p.m. outside a 24 Hour Fitness at 3701 Louisiana St.

Houston police said the man was placing his daughter in the back seat of his vehicle when he was shot by 27-year-old Joey Harper.

The 6-year-old girl yelled, "Papi, papi!" and covered her eyes during the shooting, family members told KPRC2

Police said the father tackled Harper after he had been shot, and knocked him out of the wheelchair, but Harper wrestled away and escaped in his wheelchair.

The 39-year-old father was taken to a local hospital in critical condition.

Family members said the victim was shot twice -- in the torso and the side. He was in surgery for eight hours on Monday.

A witness saw Harper leave the scene in the wheelchair and followed him to a CVS parking lot three blocks away, police said. Harper was attempting to leave in a friend's vehicle when officers arrested him.

Police said Harper was still in possession of the mask and a pistol when they found him.

Harper is facing a charge of felon in possession of a weapon. Additional charges are likely forthcoming.

“It just makes my heart drop,” said Bella Lockworth, who works out at that 24 Hour Fitness location. “I feel like the daughter’s going to be traumatized from this.”

“Shocking, I mean, you wouldn’t expect that sort of thing to happen here,” said Josh Hamm, who also works out there.