PSNI officers investigating the murder of Emmett Shiels in Derry have released a 33-year-old man who had been questioned about the killing.
A 17-year-old youth who went voluntarily to police yesterday, and has also been questioned, remains in custody.
Last night British army bomb experts examined a car which police suspect may be linked to the murder of Mr Shiels.
It was taken away for further forensic examination.
It is believed that the 22-year-old pizza delivery driver was shot after he intervened in a dispute in the Creggan area of the city just after 1am on Tuesday.
Mr Shiels died later in hospital.
