Police in Northern Ireland are treating the death of prison officer Adrian Ismay as murder after a post mortem found he died as a result of injuries sustained in a bomb attack.
Mr Ismay, from east Belfast, is believed to have suffered a heart attack a number of days after a device partially detonated under the van he was driving at Hillsborough Drive on March 4th.
Detectives from the PSNI Serious Crime Branch on Wednesday started a murder investigation following the results of the post mortem.
Senior investigating officer detective chief inspector Richard Campbell said, "today is yet another difficult day for the Ismay family, his friends and colleagues as they struggle to come to terms with the events of the past 12 days. We have spoken to the family this morning and advised them of this development.
“We are also liaising with the Public Prosecution Service in relation to the individual who is currently charged with attempted murder and causing an explosion with intent to endanger life.”
Mr Campbell added: “this has been treated as a significant serious crime investigation from the outset and will continue as such. I would reiterate my appeal from yesterday about the two vehicles we believe were involved in this murder. The cars were a red Citroen C3 with registration SKZ6662 and a silver Skoda Fabia with registration KFZ2352.”
At the time of the attack, it is understood Mr Ismay, a married father of three grown-up daughters, had been on his way to work at Hydebank Wood Young Offenders Centre where he trained staff based at Maghaberry top-security prison.
The New IRA claimed responsibility for the bomb at the time and linked it to a dispute between the prison authorities at Maghaberry and dissident republican inmates.
A 45-year-old man last week appeared at court in Belfast charged with attempted murder and explosives offences.