May 4, 2013 7:43 PM by Sam Salzwedel
TUCSON - The family of Robert Pena is hoping somebody will turn in his killer.
Tucson Police found him at a gas station at 6th Avenue and Valencia Road April 21, 2011. He was in a coma and died May 7.
His sister, Irene Zamora, organized her family to walk in his memory and keep the case visible to the public.
"I was there when he took his last breath," Zamora said. "I had some peace when he left, but it was the hardest thing to see what they did to him."
Investigators and the family have not been specific, but he died of a head injury.
Pena was 54 years old and homeless when he died, but he grew up in Tucson and had 7 siblings.
Zamora struggles to stay hopeful detectives will find her brothers murderer.
"It will give me a little bit of peace knowing that person can't do it to another family member or to someone else out there," she said, "so they don't have to go through the heartache and the life change that we have to go through."