Breakthroughs in forensic science have prompted a complete review of all the evidence found at the scene where Wayne Trotter was murdered.

In the first major development in the investigation in over a year, senior officers have called for extensive DNA testing on all artefacts found since the inquiry began.

On December 5, 2002, Mr Trotter was doused in petrol and burnt alive on the Farriers Way estate in Borehamwood and nearly three years on, his killers are yet to be found.

The 30-year-old was killed in Dales Path, just yards from his home, his wife, who was pregnant with his daughter, and his three-year-old son.

Mr Trotter was walking home at about midnight from Furzehill Road, after taking a bus from Elstree and Borehamwood railway station. He was returning after a day's work as a shift team leader at a plastics factory in Hendon.

Detective Superintendent Ken Bell, senior investigating officer in the case, said: "Forensic science has come a long way in the past couple of years and new developments have come in. We have to retest everything to ensure we miss nothing.

"We have had little response from the public, and no substantial information whatsoever. At the end of the day, someone out there knows who did this.

"This case will not end until someone is behind bars paying for what they've done. If it takes months, years or even decades, the people or person who carried out this horrific murder will one day get a knock on their door we can promise them that."

Vital evidence found at the scene which will now be re-examined includes a petrol can, a baseball cap, a glove, a pen knife and a piece of cloth wrapped around a stick.

Vicky Cooledge, Wayne's mother, this week said she would not rest until his killers are found.

"Nearly three years on, I can say time is not a healer," she said.

"I feel as bad today, if not worse, than I felt at the beginning. When it first happened, there was hope as it was so high-profile, but now it seems to have gone very quiet. You start thinking, are they ever going to catch anyone?

"I promised Wayne I wouldn't rest until justice was served, and I feel I've got to do everything in my power to make that happen."

Police are appealing for anyone who has any information about the incident to come forward, and speak to them in confidence. They stress that no call relating to this inquiry would be wasted.

Anyone with any information at all should call the incident appeal line on 01707 354236, or Crimestoppers, anonymously, on 0800 555 111.