Amandu Koroma was found dead in the Potomac River on Feb. 9, 1991 near the Woodrow Wilson Bridge by a police officer on patrol.
It wasn't until recently that police figured out who he was.
Now investigators are reaching out to the public for help with the case.
Using an updated fingerprinting database and technology, and with help from the Federal Bureau of Investigation, Natural Resources police investigators were able to match Koroma's fingerprints to ones taken from him in a 1990 arrest, said Cpl. Mike Lathroum, of Maryland Natural Resources Police.
"We know who he is," Lathroum said. "Now we're trying to notify next-of-kin and figure out why he died."
The case is one of two cold cases currently under investigation by Natural Resources Police.
Koroma, originally from Sierra Leone, was 31 when he died. His last place of residence was on 7th Street in northwest Washington, D.C.
His parents have been identified as Aruna and Kaitnu Koroma, although police do not know whether they are still alive.
He is described as about five foot five in height and weighing approximately 130 pounds, with a scar on his right arm and a birthmark on his left cheek.
He was found wearing unique black shoes with a gold fleur-de-lis design, a necklace charm with an "A" and a spade and a leather wrist watch.
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Lathroum said Koroma was arrested in Washington in 1990. Online court records show the case was closed, and do not list what he was charged with.
Maryland court records show he was charged in 1990 with driving while impaired by alcohol and making an improper lane change.
Lathroum said it's likely he had been in the water for days before he was found.
The Office of the Medical Examiner determined his death was caused by drowning.
Investigators do not suspect foul play, Lathroum said, as there were no obvious signs of trauma.
An autopsy performed on Koroma's body found no drugs in his system, and a trace amount of alcohol that is probably a result of decomposition, Lathroum said.
Anyone with information about Koroma or the whereabouts of his family in the U.S. or Africa is asked to contact Lathroum at firstname.lastname@example.org or by calling 410-260-8888. Callers may remain anonymous.