The killer remains at large a year after a Dallas man was shot execution style while walking his dog.
Alvin Joseph was killed last March in the 9900 block of Adelta Boulevard near Skillman Street, and detectives have nothing so far in the case.
"We lost a beautiful child. Somebody just took him away from us," said Joseph's grandmother, Harline Anderson.
She described her grandson as a gentle giant. Joseph stood a broad 6-feet tall and weighed 300 pounds. He was the kind of guy who would seem to be invincible. He had no criminal record and his family said no enemies.
"This man wasn't bothering nobody. All he ever wanted to do was raise his children," Anderson said.
Joseph had twin daughters, Briana and Kiana, who were just 8 years old when they lost their father. His family said he worked hard for those girls.
On the night he was shot, he was winding down from a long day on the job and on a midnight walk with his terrier, Flip. He never saw it coming.
"Flip was just barking, barking, barking. He wouldn't let anybody touch him. When the officer got there, they tried to touch Alvin. Flip wouldn't let anybody get at Alvin," said Joseph's mother, Pamela Joseph.
Alvin Joseph was shot in the face. Dallas police detectives said the shooting was unprovoked and without warning.
After he was shot, he was somewhat alert and told officers the gunman came out of a pedestrian gate, walked right up to him and fired.
Alvin Joseph said the gunman then turned around and walked back into the gate.
A day later, with his mother at his bedside, he died.
"I was talking to him and I was telling him, 'Baby, mama's here,' and he looked at me and he blinked his eyes and he looked at me again. And after that, the machine's just started going off," Pamela Joseph said of her son.
The crime has haunted the lead Dallas police detective on the case, Michael Yeric.
"We're not any closer now than we were a year ago," he said.
NBC 5 was granted rare access into the Dallas Police Cold Case Unit where retractable shelving units contain details on countless unsolved murders.
"Each one of these was a person," Yeric said.
But there's one file, Alvin Joseph's, that for now, doesn't leave Yeric's desk.
"We recovered his cell phone at the scene. I keep that with me. He was on the phone at the time of the offense," said Yeric.
Aside from bullet fragments recovered during Alvin Joseph's surgery to save his life, his phone is the only piece of possible evidence left.
Yeric is on a crusade for justice for Alvin Joseph, and so is his family.
"We're trying to get an answer to whatever happened," said his grandmother. "So we can rest with piece of mind."
Dallas police are asking for the public's help in solving Alvin Joseph's case. A cash reward is being offered for information that leads to a viable arrest.