The partner of a police sergeant killed in a custody cell has said he was let down by the "shoddy and inadequate" performance of the Metropolitan Police.
Sgt Matiu Ratana, known as Matt, was murdered in September 2020 after officers failed to find a gun concealed on arrested man Louis De Zoysa.
Su Bushby, speaking after an inquest verdict of unlawful killing, said police failures left her "devastated".
"If people had done their job properly, Matt would still be alive today".
The New Zealand-born officer, 54, who had served in the Met Police for almost 30 years and was three months from retirement, was hit in the chest by the first of three shots discharged in three seconds by De Zoysa.
He had been arrested and searched but managed to hide an antique revolver in an underarm holster.
In recording her verdict at the conclusion of the inquest at Croydon Town Hall on Monday, senior coroner Sarah Ormond-Walshe said there was a "failure to carry out a safe, thorough and systematic search".
The court had heard how on arriving at Croydon's Windmill Road custody centre, De Zoysa managed to move his handcuffed arms from behind his back to fire at Sgt Ratana.
'Vulnerable to murder'
The court heard PC Richard Davey, who was still working his probation period, carried out a search while his more experienced colleague, PC Samantha Still, assisted.
PC Davey admitted he "abandoned his training" and should have discovered the weapon during the arrest in London Road, Norbury.
In the custody van, De Zoysa was seen in footage wriggling and jerking, which according to expert evidence was him repositioning the firearm to his hands.
Ms Bushby said: "The shoddy and inadequate search undertaken by the police officers was a neglect of their duty and left Matt vulnerable to murder.
"The number of failures, the gravity of them and the impact of both the search failures and failures in the transportation of De Zoysa to the police station that have come out during the evidence in this inquest has left me devastated.
"It is my view that Matt has been let down by the Metropolitan Police.
"Matt gave so much to the Metropolitan Police and its failures to protect him on that night are now clear for all to see.
"The search should have been thorough, safe and systematic for it to be effective - it was none of those things.
"If it was an effective search, the gun would have been found on De Zoysa and Matt would be alive now."
Ms Bushby said there "must be" improvements to searches of suspects and security arrangements in police stations, adding: "I do not want Matt's death to be in vain."
She went on: "Not once, during the past three years, has anyone from the Metropolitan Police informed me that there was any issue with the search on that fateful night.
"I have not been informed by anyone during this time that the actions of the Metropolitan Police may have contributed towards Matt's death.
"If the Metropolitan Police had been more open and transparent with me about their failings, it would have gone a long way to making the last few weeks of this inquest easier."
De Zoysa is serving a whole-life jail term for Sgt Ratana's murder after a trial earlier this year, during which his legal team said he was suffering an autistic meltdown at the time of the shooting.
Met Police deputy assistant commissioner Stuart Cundy, said: "The arresting officers recognised that their search and observations of De Zoysa could have been more systematic, and should have found the firearm.
"Later at the police station these same officers showed great courage in disarming De Zoysa whilst he continued to fire the gun. I admire their bravery and that of everyone who was in the custody centre that night.
"Matt Ratana's murder was a stark and terrible reminder of the risks and challenges police officers and staff undertake every time they turn up for work.
"We will never forget Matt and will continue to honour his legacy, which will live on through his family, his many friends and colleagues in the Met, in his rugby foundation and beyond."