The man named as Simeon Francis was arrested on May 20 in Exeter and booked into custody at Torquay Police Station, the Independent Office for Police Conduct (IOPC) said. The detainee was “found unresponsive in his cell” and an ambulance was called. He was pronounced dead at around 6pm on the same day.
The case is being investigated by the watchdog.
It said Mr Francis was 35 years old.
No cause of death was identified in a preliminary post-mortem examination.
Further tests are being carried out.
IOPC regional rirector Catrin Evans said: “Our thoughts are with Mr Francis’ family and friends following his death.
“We will be keeping his family updated during the course of our independent investigation.
“Our investigators have begun gathering evidence and statements from officers.
“We are analysing a considerable amount of CCTV footage from the custody suite.
“We are looking at the level of care provided during the period of detention, including the frequency and adequacy of checks carried out.”
The IOPC said Mr Francis was arrested at around 12.45am on May 20 in Cowley Bridge Road, Exeter.
He was taken to the station in a police van.
At around 3am he was booked into custody.
The watchdog’s investigation comes after a mandatory referral from Devon and Cornwall Police.
An inquest into Mr Francis’s death was opened and adjourned last week by the Plymouth Coroner.
The announcement from the IOPC comes on the back of days of Black Lives Matter protests in UK cities.
Street rallies were held over the weekend in London, Manchester, Cardiff, Sheffield, Newcastle, Derby, Wolverhampton, Wrexham among other cities.
While the death of the African-American man George Floyd in Minneapolis initially sparked the protests in Britain, they have since taken on a broader call for an end to racism.
This is a breaking news story. More to follow…
Published at Mon, 08 Jun 2020 15:32:00 +0000