It has been described by racial justice campaigners as one of Yorkshire's most shameful episodes.
Nigerian immigrant David Oluwale came to Britain in 1949 to work, aged 19, sailing into Hull on a cargo ship and then travelling to Leeds.
His initial experiences were good, helping to rebuild post-war Britain and enjoying the night life of a developing northern city.
But his life increasingly became characterised by mental ill-health, homelessness, racism, destitution and police persecution.
He spent his time in and out of prison, on the streets in Leeds city centre and at the infamous High Royds psychiatric hospital in Menston.
After his release he was targeted by two Leeds Police officers and was systematically beaten right up until his death.
A tragic end
In April 1969, Oluwale was seen running towards the River Aire. He was holding the back of his head with his hands.
On 4 May his badly beaten body was pulled from the water.
Unstable and vulnerable, he had been chased to his death by those whose very job was to protect him.
Those men were Inspector Geoffrey Ellerker and Sergeant Kenneth Kitching.
Oluwale drowned trying to avoid a further beating. The river, he thought, was his only escape.
The officers were charged with his manslaughter, but, in a controversial direction by the judge, they were acquitted in November 1971.
Nevertheless, based on the evidence of Police Cadet Gary Galvin and his contemporaries, the two officers were convicted of assaulting Oluwale.
But Ellerker and Kitching were given jail sentences in no way reflective of their crime. Ellerker received 36 months, Kitching 30 months.
When David Oluwale was buried the only people there to mourn were the undertakers.
Since his death, at the age of 38, David Oluwale has been held up as the first documented victim of racist policing.
And efforts have continued to ensure that his death was not in vain.
Remember Oluwale – the David Oluwale Memorial Association, campaigns to keep his memory alive.
In recent months a bridge and, most recently, a plaque have been unveiled in David Oluwale's honour close to where he died.