The family of a man shot dead by Sussex Police while naked in his own flat has been given permission to sue the force for unlawful killing.
Three Court of Appeal judges headed by the Master of the Rolls, Sir Anthony Clarke, ruled that there should be a civil trial on the issue of whether the police marksman, PC Chris Sherwood, was guilty of assault and battery when he shot James Ashley.
The Appeal Court has also given permission for allegations of wrongful conduct in office by the chief constable of Sussex after the shooting to go to trial.
James Ashley was 39 when he was killed during a police raid on his flat in St Leonards, East Sussex, in the early hours of January 1998.
Sussex police had a warrant to search his flat in a drugs operation. When his door was forced open, Ashley got up from the bed he was sharing with his girlfriend and went towards the door. He was shot by PC Sherwood in the neck.
James?s father and son are bringing civil claims against the Chief Constable. Some of these claims arise out of the shooting itself - for assault and battery, false imprisonment and negligence.
Police must now show that PC Sherwood, who has been acquitted in a criminal trial of murder, acted in self defence or a declaration could be made of unlawful killing.
The Ashley family also claims misfeasance and negligence, arising out of the conduct of the police after the shooting.
Misfeasant conduct is conduct by a public officer intending to damage someone, or knowing that or being reckless as to whether he is acting unlawfully and that he might injure someone.
The family claims that the officers concerned, and in particular Chief Constable Paul Whitehouse who retired in 2001, deliberately released incorrect information to the Press and public, obstructed an independent investigation, failed to involve the Ashley family and fabricated evidence in circumstances in which they knew that what they were doing was unlawful.
The Chief Constable has already admitted negligence in the shooting claim. The amount of compensation for the family is to be set at the same time as the trial over assault and battery, which relates to the shooting.
Sir Anthony ordered that any trial over misfeasance should wait until after the amount of damages has been settled.
Edward Faulks QC, who represented the police during the hearing, told the judges that the trial would set important and troubling legal precedents.
"The self defence issue is a point of great constitutional importance," warned Mr Faulks. "The effect of this court?s order is that there will be a murder trial which could result in a declaration of unlawful killing."
His application to appeal the ruling to the House of Lords was refused.
Sir Anthony said that he thought it was in the public interest for the case to be tested in the civil courts.
A criminal prosecution must disprove the shooting was an honest mistake - its reasonableness was irrelevant. In civil proceedings, the defendant must prove that the mistake was reasonable.
"There is, to my mind, a public interest in allowing this aspect of the claim against the police to proceed," said Sir Anthony.
The appeal judges said that the family had a real prospect of proving the allegations, overturning the decision of the High Court.
The Ashley family solicitors, Deighton Guedalla, said: "Today?s ruling opens the door for the family to put the Chief Constable of Sussex on trial at the High Court for unlawfully killing James Ashley and for misfeasant conduct after James Ashley?s death."
The victim?s father, also called James, said: "I am happy that a court has reached a positive decision after eight years."
James Ashley?s son, James, said: "Nothing will ever bring my dad back, but I am very pleased with the outcome of this appeal. Maybe our family will now get some answers."
The family has long called for a full public inquiry into the shooting. Sir Anthony warned however that it was not the purpose of a private law claim to play the part of a public inquiry.
"There is no doubt that the appellants (father and son) would like there to have been a public inquiry and that they hope that a civil action will to some extent fill the gap, but it does not seem to me to follow from that that the claim for a declaration that Pc Sherwood and the respondent (the Chief Constable) are liable in battery is an abuse of the process."
Sir Anthony said the family should be permitted to take the battery issue to court "if only in order to seek a declaration that the deceased was unlawfully killed by Pc Sherwood, especially in circumstances in which there has been no inquest or public inquiry into the death".
He said the role of the civil courts was not solely to provide compensation.
"The pursuit of a declaration that the respondent is liable in the tort of battery for the shooting of the deceased by Pc Sherwood is a remedy available to the court."
He added: "On the facts here, it is true that PC Sherwood was acquitted of murder on the direction of the trial judge. However, at that trial the standard and burden of proof and the ingredients of the alleged offence were different from the standard and burden of proof and the ingredients of the tort of battery."