Police investigating the murder of a man who was doused in petrol and set alight just yards from his home said yesterday he may have merely been "in the wrong place at the wrong time".

Neighbours heard Wayne Trotter, 30, screaming in agony and rushed out of their homes to try to smother the flames.

Police said Mr Trotter was a devoted family man with no known enemies. They are looking for three youths seen in the area at the time of the attack, which happened in an alley in Borehamwood, Hertfordshire, in the early hours of Thursday.

Appealing directly to those involved, Detective Superintendent Steve Read said: "I am asking them to think about how much worse it will be for you if we have to come and get you – and I assure you we will. It's possible that of the group present, not all were responsible for the attack."

Det Supt Read added: "It still appears to be a completely motiveless attack on an innocent family man, who perhaps was in the wrong place at the wrong time. This was an appalling and ferocious attack."

Mr Trotter had been on his way home from work at a plastics factory in Hendon, north London. He caught a 107 or 292 bus from Elstree and Borehamwood railway station and got off near the junction of Barnet Lane and Furzehill Road. He then walked along Farriers Way and cut into Dales Path, where he was found ablaze.

Among those who tried to tend to Mr Trotter was his pregnant wife, Anne, a nurse. The couple had a three-year-old son.

Mr Trotter was taken by ambulance to Barnet General hospital before being transferred to the Chelsea and Westminster hospital, where he died.

Yesterday one local, who did not want to be named, said the area had deteriorated over the past few years with youths running rampage. He said: "The youths, or thugs, whatever you want to call them, are doing what they want and the law really don't stop them to that great a deal."