The family of a murdered doctor said last night they were considering a judicial review of the "unacceptable" decision not to prosecute the man named by a High Court judge as her killer.
Despite Mr Tony Diedrick being the prime suspect in the murder of his ex-girlfriend, the Crown Prosecution Service ruled there was not enough evidence to bring a criminal case.
Dr Francisco's family brought an unprecedented civil case for assault and battery, at the end of which the judge said he found the murder proved.
Mr Justice Alliott ruled in March that Mr Diedrick (38) "struck and then strangled" Dr Francisco at her central London flat on Boxing Day 1994.
Following that ruling the CPS pledged to re-examine the case. However yesterday it said a fresh police report contained no new evidence and so the original decision not to prosecute stood.
The High Court heard that Mr Diedrick stalked 27-year-old Dr Francisco for months out of a "violent and perverted obsession" before strangling her with a vacuum cleaner flex.
The case was the first in which someone who had never been charged with a criminal offence was found guilty in a civil case. It was proved "on the balance of probabilities" but not to the criminal standard of "beyond reasonable doubt".
But Dr Francisco's family reacted angrily to the CPS decision. Her mother, Venus, said: "I cannot find words to express my anger and dissatisfaction. I am utterly disgusted and disappointed with the CPS for thinking so little of the life of a human being. We will fight on until Joan's killer has been put behind bars and justice is seen to be done." She said the case would have been handled differently if her daughter had been white.
The family's solicitor, Ms Caron Thatcher, compared the family's position to the case of murdered black teenager Stephen Lawrence. Despite five men being charged with his murder at various times, no one has been convicted of his killing.
Commander Paddy Tomkins, head of crime investigation in Central London, said his detectives were "continuing our investigations in a determined effort to bring her [Ms Francisco's] killer to justice".