It's still unclear what the motive was behind the brutal beating that led to the death of Robert Pena two years ago.
The 53-year-old had just left the Circle K convenience store near Valencia and South Sixth when he was confronted by some person or some group of people who changed everything in an instant.
"I understand that Robert had gone to that area and he may have been with other people at the time," says Joseph Savalas, the victim's oldest sibling.
Other people who could very well know what happened to Robert Pena.
Or perhaps, even be responsible for what happened to him back on April 21, 2011.
"My brother was essentially beaten," Savalas says. "He was beaten with a tool that we understand. It was a horrible thing amongst other things that were done to him."
Pena died from those injuries just a short time later.
Within weeks, two potential suspects were brought in by police, but eventually released due to a lack of evidence.
Devastating news to Pena's family, especially his oldest brother who worked more than 23 years in law enforcement.
"These are individuals that were detained and for whatever reason, let go, and it's probably the closest thing that we have had to a lead or anything as far as family goes," Savalas says.
But this family isn't giving up hope.
Last weekend they gathered near Valencia and South Sixth Avenue in an effort to raise awareness about their loved one's case.
Over the last two years somebody's been ripping down fliers offering a reward for information leading to an arrest in Pena's murder.
The victim's sister has some ideas who might be doing that.
"Somebody knows who this person or these persons that did that," says Irene Zamora, tears welling in her eyes. "They don't want them caught. But stop and think about your family, if it was you going through this. How would you feel?"
Which is why authorities and Robert Pena's family are asking for your help.
Somebody out there has some idea what happened that April night in 2011.
If that person is you, you're asked to call 911 or 88-CRIME, the Pima County Attorney's anonymous tip line.
"It's hard," Zamora says. "We wait and see if they're gonna call you -- and they don't."
A reward up to $1,000 will go to the person whose tip leads to an arrest in this unsolved case.
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