Published Thursday, 12 November 2009
The 30-year-old was hacked and beaten to death in front of his pregnant wife and his daughter at his Fallswater Street home last February.
In the dock denying the murder are Derry men 34-year-old Christopher Stokes, 38-year-old Edward Gabriel Stokes and a 16-year-old boy who cannot be named because of his age.
Assistant State Pathologist for Northern Ireland, Dr. Peter Ingram told the Belfast Crown Court jury he believed the attackers inflicted between 30 and 40 knife wounds on the victim - some after he was already dead.
He told prosecuting QC Gordon Kerr the main cause of death would have been a wound which had sliced through an artery, causing "torrential bleeding".
This, said the doctor, would have caused his "rapid but not immediate death".
He said there was also one wound to Mr Mongan's head which was so deep the underlying skull was visible.
"Many of the injuries could have been caused by blows from a bladed weapon such as a knife but others could have been caused by multiple blows from a bladed weapon such as a machete, hatchet or an axe with a sharp cutting edge," said Dr Ingram.
Asked by Mr Kerr if he could say anything about the minimum number of weapons used, the doctor replied: "I would say at the very least, two".
It was while under cross examination by defence SC Philip Magee, acting for Christopher Stokes, that the pathologist agreed that some of the wounds to Mr Mongan's legs had not bled as profusely, indicating the possibility that he was most likely dead when they were inflicted.
Asked by Dermot Fee QC, acting for Edward Stokes, if there was any injury consistent with him being hit with a baseball bat or baton, Dr Ingram revealed that each and every injury sustained had been "as a result of sharp, bladed weapons" with no injuries suggesting he had been hit with any blunt weapon.
The trial, which is at hearing, continues.