A 23-year-old man has been arrested on suspicion of the murder of Met Police Sergeant Matt Ratana.
Sgt Ratana was allegedly shot in Croydon Custody Centre in south London on September 25.
The suspect, who was in the custody centre having been arrested for a separate offence, was found to have suffered a gunshot wound himself.
He was in a critical condition but today Metropolitan Police said he has stabilised and his injuries are no longer life-threatening.
Therefore he has now been arrested on suspicion of murder.
However, he remains in hospital and police will be liaising with medics regarding when he may be fit to be quizzed by detectives.
Sgt Ratana’s partner, son and family continue to be supported by family liaison officers.
A Metropolitan Police spokesperson said: “At approximately 2.15am, on Friday, September 25, Sergeant Ratana was shot at Croydon Custody Centre in Windmill Lane.
“Officers and paramedics treated him at the scene and he was taken to hospital by London Ambulance Service. Very tragically he subsequently died at hospital.
“A 23-year-old man, who had been arrested for a separate offence, was detained by officers at Croydon Custody Centre and then taken by ambulance to hospital with a gunshot wound.
“No police firearms were discharged during the incident.
“The man’s condition, originally critical, has since stabilised and is no longer considered life-threatening.
“Therefore, on Friday, November 13, he was considered fit to be arrested on suspicion of murder.
“However, as the man remains in hospital, officers will liaise with the relevant medical and legal teams to make an assessment of when he will be fit for interview.
“Specialist family liaison officers from the Met’s Specialist Crime Command are in regular contact with and supporting Matt’s partner, his son and wider family.
“They have been informed of today’s arrest.”
At Sgt Ratana’s funeral, a tribute from his son Luke read: “My dad was certainly larger than life and a man loved by so many people.
“It is deeply touching to see tributes paid to him and outpouring of love from friends, family, the rugby community, the people of the United Kingdom and beyond.
“It makes me very proud to see the impact he ha shad and how he touched the lives of so many.”
The touching tribute from Luke ended with: “Goodbye dad, rest in peace, until we meet again.”
In a video dedicated to the committed police officer, his colleagues desrcribed him as a “huge personality and a huge loss”.
Others said he was “funny”, “larger than life”, “genuine”, “funny”, “loud”, “courageous” and ” one of the funniest men I have ever met”.
Sgt Ratana was originally from New Zealand and joined the Met in 1991. He was previously a protection officer to Princess Diana, the Queen Mother and ex-Prime Minister John Major.
The officer, who lived in Worthing, West Sussex, and was head coach for East Grinstead Rugby Club, was 300 yards from an IRA bomb that went off outside 10 Downing Street in 1992.
Met Commissioner Dame Cressida Dick described him as a “talented officer” who was “big in heart”.
Sgt Ratana’s partner Su Bushby, also paid tribute, saying: “There aren’t really any words for how I am feeling right now about the loss of Matt; about losing someone I loved, and was so close to, in such a tragic manner.
“I know Matt touched many, many people’s lives with his friendliness, patience, kindness, enthusiasm and caring ways.
“I had the pleasure of sharing five years of my life with this lovely man – my gentle giant, with his infectious smile and big heart. I think of him with tenderness and love.
“Matt was my partner, friend, confidant, support and soul mate.
“He will be greatly missed but never forgotten. Matt will always be in my head and in my heart.”
Sgt Ratana was also recalled as a popular rugby coach and top police officer.
East Grinstead Rugby Club, where he was head coach, described him as “an irreplaceable figure”.