Barry McCrory: Police issue warning about Londonderry murder
11 October 2013 Last updated at 14:04 BST
Police investigating the murder of Barry McCrory in Derry on Thursday have released the name of a man they want to speak to.
In an unusual move, officers have requested information on the whereabouts of 58-year-old Kieran McLaughlin.
Mr McCrory, who was 35, was shot dead at a flat in Shipquay Street on Thursday morning.
Several hundred people, including the family of Barry McCrory, gathered at Guildhall Square on Friday to say "no to violence".
Keiron Tourish reports.