KANSAS CITY, KAN. — Calling it a potentially racially motivated crime, federal authorities offered a $100,000 reward Thursday in a 16-year-old cold case involving a black man whose body was found in a creek in Kansas.

The FBI reopened the investigation a more than a year ago into the death of 23-year-old Alonzo Brooks, whose body was found in La Cygne, Kansas, on May 1, 2004, the U.S. attorney’s office said in a news release.

Investigators reviewed the evidence and re-interviewed witnesses who attended a party at a farmhouse where Brooks was last seen alive. They also interviewed new witnesses and collected forensic evidence.

Brooks was one of only three black men at the party he attended with about 100 people at a farmhouse on the outskirts of La Cygne. Brooks rode to the party with friends, but they left before him and he eventually had no ride home to Gardner, Kansas, where he lived.

His family and friends contacted the Linn County Sheriff’s Department when he failed to come home the next day. His body was found a month later by a group of family and friends who organized a search. An autopsy did not determine a cause of death.