. >>> it was 28 years ago this weekend that virginia state trooper johnny rushbowman answered the doorhis home and was stabbed more than 40 times before he died. his murderer never caught. there's a renewed effort to solve this case. a new $50,000 reward is offered this week in hopes someone will come forward after all this time. gary nurenberg is here with what remains the only unsolved murder of a virginia state trooper. gary. >> reporter: someone killed the trooper and got away with it, anita. the murderer left evidence behind, though, and technology has come a long way since 1984. new techniques and old evidence have now come together to give investigators a sense of optimism. the 31-year-old trooper had left the marine corps to join the virginia state police. was married with a 2-year-old daughter when he answered just after 4:00 in the morning the pounding on his door by someone claiming to be from the power company. >> it was the fact that a person with a knife had multiple stab wounds to the chest and throat and neck. >> reporter: bowman's wife called police at 4:18 a.m. . >> m