Kansas City, Mo. ? They don’t have a body, a missing person report, or even a name.

But Kansas City police are investigating a possible homicide from the mid-1980s, after a man came forward with information about the victim, why he was killed, who had done it and where the body was dumped.

Police said they were skeptical at first, but began to believe the man because he had such specific information.

“The story seemed so convincing, you could not not believe him,” said Detective Anthony Cooper of the cold case squad. “The things we would expect him to recollect he did, and the things we didn’t expect him to recollect, he didn’t.”

The man even took detectives to a remote bank of the Missouri River on Tuesday where the body supposedly was dumped. No human remains were found.

The lack of remains doesn’t mean a homicide didn’t occur, said Sgt. John Jackson of the cold case homicide squad, because two major floods hit the area since the 1980s.

Police are hoping someone will come forward who remembers an 18- or 19-year-old man who might have disappeared in 1984 or 1985 from the Century 37 apartments in Kansas City. The man was said to be white, of average height and weight with shoulder-length brown hair. He reportedly was from Riverside, and frequented Line Creek Park.

Police refused to reveal how the victim was killed.

Cooper acknowledged that the investigation was unusual.

“This guy literally just fell out of the sky,” he said of the informant.