A £10,000 reward is being offered over the murder of a man and the kidnap and possible murder of a second man.
Daniel Shaw, 28, was shot near or at his home in Torrington Avenue in Coventry on 25 March. He was found with a chest injury in nearby Copland Place.
Police believe John Robbins, 33, was kidnapped and taken to Torrington Avenue and "violently assaulted" and has not been seen since 21 March.
His disappearance has raised fears he has also been killed, police said.
Crimestoppers said the reward was being offered for information that led to the arrest and conviction of those responsible for Mr Shaw's murder and the kidnapping, disappearance and possible murder of Mr Robbins.
Pauline Hadley, West Midlands Regional Manager, said: "A young man has been murdered and another has disappeared in suspicious circumstances.
"It's deeply distressing for family and friends and also for the wider community to know that such violence is taking place in their midst."
Mr Shaw was confirmed dead at the scene in Tile Hill as a result of a gunshot wound to the chest.
Two men arrested on 27 March on suspicion of conspiracy to murder Mr Shaw have been released on bail by police.
Detectives believe Mr Robbins was assaulted inside a property in Torrington Avenue. His disappearance has been described as "out of character".