RUC detectives investigating the murder of a 25-year-old Catholic father of four in Coleraine, Co Derry, late on Saturday night believe loyalist paramilitaries were responsible.
Mr John Henry McCormick was shot as he tried to flee his Loughanhill Park home just after 10.30 p.m. on Saturday after two masked gunmen forced their way into his home.
Mr McCormick, whose partner, Ms Lynn McConnell, is expecting their fifth child in September, is understood to have been visited by RUC officers last Thursday and advised about his personal safety.
Last month his home was slightly damaged in a pipe-bomb attack, and it is believed he narrowly escaped being abducted by loyalists in recent weeks.
The murder was carried out when the two gunmen, both wearing boiler suits and armed with handguns, burst into Mr McCormick's home through the back door.
Chief Insp Nigel Kyle, who is leading the murder investigation, said the attack was cold-blooded.
"We are investigating several possible motives and we have our suspicions," he said.
"We are following several lines of inquiry at the moment but we believe at this stage that loyalist paramilitaries were involved. The silver-coloured Renault 11 car which was used by the gunmen was found burnt out a short distance from the scene of the murder at Dundoin Road, and I am appealing to anyone who may have seen this vehicle on Saturday night to contact the investigating detectives as soon as possible," he added.