A £20,000 reward has been offered by police investigating the killing of a man shot in the head in what detectives believe was a case of mistaken identity.
Officers have yet to find a motive for the murder of Wayne Stockdale, 42, after he was gunned down while riding his bicycle by two masked men carrying handguns.
Mr Stockdale, from Poplar, east London, died four days after being shot in Rounton Road, Bow, east London, four years ago today.
Five people were arrested over the 2011 crime but were later released without charge.
His attackers were believed to have also fired shots at a group near shops in Devons Road before making off and are described by police as either black or Asian in appearance, with their faces covered.
A Metropolitan Police statement said: "In all the inquiries so far carried out detectives have not found any evidence of motive, or even a reason why Wayne would have been targeted. It is believed he may have been shot as a result of mistaken identity."
Acting Detective Inspector Peter Hine, leading the investigation for the Met's Trident Legacy Team, said: "It's now four years since Wayne, we believe, was innocently murdered, leaving a family waiting for his killers to be brought to justice.
"We have always maintained that Wayne was not the intended target for this incident, which saw shots fired both at him and into the street.
"We are appealing for anyone who knows what happened that night to contact us. We are urging those who have remained silent all these years to think about Wayne's family and re-examine their consciences and help bring Wayne's killers before a court.
"My direct appeal to those that know who is responsible is: Trident has a history of treating the information that is passed to them in confidence, and offering support and protection to those that do the right thing and come forward help prosecute offenders."
Anyone with any information should contact the force on 020 8785 8267.