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 . I 'm the only one who can do this because I 'm 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 Baltimore 's Charles Village neighborhood for dinner with his wife . A suspect described as a thin , black , 5'10 '' 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 brother 's murder that he hopes will lead to the suspect and eventual conviction . A suspect described as a thin , black , 5'10 '' 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 brother 's 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 Thomspons 's 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 Thompson 's 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 .
Robert Thompson , July 27 , 1981 , of Baltimore , wants to find 83 killer . His brother Tommy was shot multiple times in a van while picking up dinner . Veteran offered $ 5,000 reward to find the killer , but then the case went cold . Mr Thompson has teamed up with fedora-wearing detective who is retiring .