A policeman killed in south London was shot as he took the suspect's temperature for Covid-19, according to reports.
The handcuffed suspect managed to pull a gun from his trousers and shoot the police officer before shooting himself, the Sun reports.
The officer was shot by a man being detained at Croydon Custody Centre and tragically died from his injuries in hospital.
A 23-year-old man who was being detained is in a critical condition with gunshot wounds.
Reports said the incident took place in the station yard as the suspect was being taken out of a police van.
He was said to have been in the process of being searched before entering the building when the shots were fired.
Police, who have launched a murder investigation, said no police firearms were discharged during the incident.
A man who has been arrested and spent time in the custody sweet said it was “impossible” to get anything in there.
The local, named MB, 33, said those arrested are searched thoroughly while a security scanner ensures no metal objects can pass into the centre.
“I do not know how this is possible - you really can’t get anything in there.
“They search you properly, I can’t think how it would be possible to get anything, never mind a gun, inside.
“There have been police stations closed down in this area in recent years - in South Norwood and Croydon, so it gets busy in there.”
Flowers were placed at the scene as locals began to gather in shock.
And devastating tributes have been paid by grieving colleagues and politicians this morning.
A number of policing colleagues have changed their social media profile pictures to black, with a blue line, as a mark of respect to the officer who was shot dead.
One officer explained: "You will see a lot of these today. It’s not politicising anything.
"It’s our family crest and unites us in times of hardship and grief. Today is not the day to challenge it’s use."
Commissioner Cressida Dick said: “This is a truly shocking incident in which one of our colleagues has lost his life in the most tragic circumstances. My heart goes out to his family, direct colleagues and friends.
“We are currently supporting his family and also have a dedicated team providing support to the officers and those in the custody centre who witnessed the shooting.
"When a colleague dies in the line of duty the shockwaves and sadness reverberates throughout the Met and our communities. Policing is a family, within London and nationally, and we will all deeply mourn our colleague.
“We are in the early stages of the investigation and are still working to establish the circumstances surrounding the incident and we will provide further updates when we have them."
The Met Police could not comment further when contacted by Mirror Online.