The partner of murdered Rachel Nickell said he had instructed lawyers to try to bring the police to account for their failings in the case.
Andre Hanscombe's son Alex witnessed the murder and sexual assault of his mother on Wimbledon Common on 15 July, 1992 at the hands of Robert Napper.
Napper was convicted in December last year, 16 years after Miss Nickell's death.
Colin Stagg spent 13 months in prison on remand after being wrongly charged with the murder.
Law firm Hickman & Rose said last night: "We are advising on remedies arising from the police failures to detain Robert Napper prior to the murder of Rachel Nickell and the subsequent long delay in establishing his responsibility for the murder.
"All possible avenues will be explored for bringing the police to account for their many failings."
Solicitor Kate Maynard said her client was not motivated by a desire for compensation but wanted "accountability and answers".
She said no decisions had yet been made about how to pursue the issue but added that a formal complaint to the police or civil proceedings "have not been ruled out".
A spokesman for the Metropolitan Police said the force could not comment as no complaint had been made.
Napper, 42, who went on to commit at least four more sex attacks, could have been caught as far back as 1989 when his mother said he had confessed to an assault.
But police could not trace the crime and did not interview him or collect his DNA.
By the time he was charged with Miss Nickell's murder, he was already in Broadmoor secure hospital for the savage killing of Samantha Bissett, 27, and her daughter, Jazmine, four.
He climbed into their basement flat near his home in Plumstead, south east London, and mutilated Miss Bissett and suffocated Jazmine after sexual assaults.
Following his conviction, police said sorry to relatives of Miss Nickell and Samantha and Jazmine Bissett for the missed opportunities to arrest Napper which could have saved their lives.
They also publicly apologised to Mr Stagg, 45, who became the chief suspect in Miss Nickell's murder and was charged following a flawed "honey-trap" laid by police.
The case was thrown out in September 1994 when police were criticised and in 2008 Mr Stagg was awarded a record £706,000 compensation from the Home Office.
It was not until 2004 that new DNA techniques were able to match a speck of DNA found on Miss Nickell's body to Napper.Reuse content