SOUTH DALLAS (CBSDFW.COM) – R.V. Johnson was 71, partially paralyzed by a stroke and was laying helpless in bed when he was murdered with a shot-gun.

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Seven years later, R.V.’s son seeks justice, even though the case has gone cold. “Though it may be cold with them, it’s very hot with me,” explained Carlton Johnson.

Carlton says he calls Dallas Police almost weekly, hoping for new leads in tracking down the gunman who killed his father “I call to get updates, to find out who’s assigned to the case and to find out what the progress is,”  said Carlton.

R.V. Johnson was a retired truck driver, left partially paralyzed on the right side of his body. In September of 2005, an intruder kicked in R.V.’s front door of his home in the 3900 block of Mehalia Drive in South Dallas.

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Police say the gunman then walked into R.V.’s bedroom and shot him in the chest. “I would say he was very much not able to defend himself,” recalled Carlton. “Someone felt they had to pull out a shot-gun to subdue him.”

R.V. Johnson

Carlton says after his father retired, he sold sandwiches and cold drinks out of a cooler to make some extra cash. The 42-year-old son believes an intruder who knew his dad may have been looking for that extra cash.

Now that his father’s murder has been moved to the cold case division, Carlton worries it will only get colder and the person who shot a defenseless man will never be brought to justice. “It’s very much frustrating. I’ll never put it to bed. I’ll never put it to rest,” Carlton added.

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Detectives are asking for the public’s help to solve this cold case. If you have any information, please call the Dallas Police Homicide Unit at 214-671-3661 or 214-671-3584. You can also call Crime Stoppers at 214-373-8477. You may remain anonymous and may receive up to $5000 for information leading to the arrest and indictment of the suspect.