No police marksmen will be prosecuted over the fatal shooting of barrister Mark Saunders.
Officials at the Crown Prosecution Service (CPS) said there is insufficient evidence to charge anyone after a siege in Chelsea, west London.
Mr Saunders died in a hail of gunfire after threatening neighbours and police with a shotgun at his multi-million pound home in Markham Square in May last year.
The decision not to prosecute any officer was approved by Director of Public Prosecutions Keir Starmer.
Legal experts considered charges of murder, attempted murder and manslaughter against seven officers who fired 11 bullets at Mr Saunders.
But they found there is no "realistic prospect" of prosecutors proving beyond reasonable doubt that the armed officers did not act in self defence.
It emerged today for the first time that they also considered gross negligence, misconduct and health and safety charges against those in charge of the operation.
Sally Walsh, of the CPS, said: "Following the Independent Police Complaints Commission (IPCC) investigation into the shooting of Mark Saunders, I have reviewed the evidence and concluded that there is insufficient evidence to charge any officer in relation to these sad events.
"The police arrived at Markham Square in Chelsea shortly before 5pm after receiving reports of shots being fired.
"A siege then began, centred on Mr Saunders' home, which lasted for more than four hours.
"The fatal shots were fired at around 9.30pm when seven officers fired 11 rounds at Mr Saunders.
"In reaching my decision, I considered charges of murder, attempted murder and manslaughter against the officers who shot, and shot at, Mr Saunders.
"All of the firearms officers have stated they were acting in self-defence or in defence of colleagues.
"It would be for the prosecution to prove that any officer was not acting in self-defence or defence of his fellow officers.
"Therefore a prosecution for any of these offences would require, amongst other things, the CPS to prove beyond reasonable doubt that the officers did not honestly and genuinely believe that either they or others were in immediate danger.
"I have decided there is no realistic prospect of proving this beyond reasonable doubt.
"I also considered charges of gross negligence manslaughter, misconduct in public office and Health and Safety At Work Act offences against the officers in charge of the operation.
"After reviewing the evidence, I have decided that there is insufficient evidence to provide a realistic prospect of a conviction against any of these officers for any of these offences.
"We recognise this was a tragic incident and that Mr Saunders was in a distressed state at the time of his death, but the police have a duty to protect the public and the right to defend themselves.
"I have informed Mrs Saunders of my decision and would again like to offer her my sympathies. I have also offered to meet her in order to provide a more detailed explanation."
Mr Saunders' widow Elizabeth said an inquest will now examine why it was necessary for police to take the fatal shots.
A statement issued by her solicitor Jane Glass said: "From the day Mark died, Elizabeth has been committed to ensuring that the circumstances of his death should be subject to the most rigorous and detailed examination.
"To that end she co-operated fully with the IPCC in its investigation and was updated regularly about its progress.
"Elizabeth now awaits the inquest which will consider in public why it was necessary for police officers to shoot her husband.
"She is concerned that nothing should be allowed to deflect attention away from the need for a full, careful and objective consideration of that question.
"Elizabeth wishes to thank her family, friends, colleagues and so many others for their unfailing kindness and continuing support since the terrible day that Mark died."Reuse content