VITAL witnesses who may have have seen the incident which led to a peacemaker being killed have yet to come forward, says the detective leading the investigation.
David Joslin, 23, was punched after trying to break up a fight in Old Church Road, Chingford, in the early hours of December 20.
He died a week later of head injuries, leaving his parents Phil and Margaret, of Kimberley Road, Chingford, and younger siblings Andrew and Lauren.
Police believe a group of people who had been drinking in the Obelisk pub had a confrontation with another group.
Barry Oliver, 29, of Littleton Avenue, Chingford, has been charged with the manslaughter of Mr Joslin and appeared at Waltham Forest Magistrates Court on New Year's Eve.
He has been remanded in custody and will appear at the Old Bailey on April 8.
Det Chief Insp John McDonald said police are still trying to trace potentially crucial witnesses.
Anybody with information about the killing, which happened shortly before 1.30am, should call police on 8345 3985.
To remain anonymous call Crimestoppers 0800 555 111.
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