A police officer from the Durham force has been found guilty of gross misconduct by a disciplinary panel, but will keep his job.
He was one of three officers involved in the arrest of Leonard McCourt, who died in custody in September 2010.
They used pepper spray on Mr McCourt after being called to a disturbance at his house in Seaham.
However, they failed to check he was alright on the journey to Peterlee police station and did not administer CPR properly.
A report by the police watchdog listed a catalogue of failures and an inquest recorded a verdict of misadventure.
The other officers involved have since left the force and no criminal charges have been brought against them.
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Sandiford, a former legal secretary originally from Redcar, was convicted of drug smuggling offences and sentenced to death in 2013.
Durham Crown Court heard that one of the male victims suffered a triple-fractured jaw, while left lying in the gutter, unconscious.