<text>  An aging veteran has only one wish before he dies, to see the man who killed his brother 34 years ago brought to justice. Robert Thompson, 83, of Baltimore, has become obsessed with the murder of his brother Tommy Thompson July 27, 1981. This is my last chance. All my brothers are dead. Im the only one who can do this because Im the only one left, he said of the cold case. Scroll down for video . Robert Thompson, pictured 83, of Baltimore, is trying to find the killer of his brother Tommy, who was shot in 1981 while picking up Chinese food . Robert left and Tommy right were close during their childhood and served together in the Korean War . Tommy Thomspon, 51, was found shot multiple times in his van after the unknown assailant entered the vehicle and forced him to drive, police say, according to the Baltimore Sun. The victim, who was shot with a .22 handgun in the stomach, leg and head, had been going to pick up Chinese takeout in Baltimores Charles Village neighborhood for dinner with his wife. A suspect described as a thin, black, 510 man with large sideburns was seen leaving the vehicle after it hit a fire hydrant, leaving Tommy Thompson inside. He had surgery to save his life, but died the next day, leaving behind four children. Robert Thompson is now looking to find the man who killed his brother, who he was close to in their childhood. The veteran, who served with his brother in the Korean War, had offered up to 5,000 as a reward to finding the suspect after the tragic event, but the case faded from . He has teamed with detective Albert Mad Dog Marcus, 65, who is looking to solve the murder before he retires after 40 years fighting crime. Mr Thompson keeps a file folder with information about his brothers murder that he hopes will lead to the suspect and eventual conviction. A suspect described as a thin, black, 510 man with large sideburns was seen leaving the van where Tommy Thompson was shot . Detective Marcus, known for wearing custom-made suits, a Fu Manchu mustache and a fedora, still has hope for the case, though solving it may not be likely. He said that new information could come in from witnesses or possible prison cell mates of the killer. Mr Thompson keeps a file folder with information about his brothers murder that he hopes will lead to the suspect and eventual conviction. His daughter Marge Zimmerman, 60, says her father has a sense of responsibility Because he has outlasted everybody, he had to bury everybody. Because he has outlasted everybody, he had to bury everybody, says Zimmerman, 60. Mr Thomsponss three brothers, two wives and son have all died. Detective Marcus is also hoping to solve three more murder cases before he retires. The Baltimore Police Department and Baltimore County Police do not list Tommy Thompsons case on their web pages for cold cases. Detective Albert Mad Dog Marcus, 65, is trying to solve four murder cases before he retires after 40 years on the force . 