The shot that killed Det Gda Adrian Donohoe during a credit union robbery seven years ago was fired from six or seven feet, a firearms expert has told the Central Criminal Court.
The jury in the trial of Aaron Brady (28), who is accused of the capital murder of the detective, was also shown a shotgun that a garda ballistics specialist said was similar to the firearm used in the fatal shooting.
Det Gda Seamus O'Donnell, of the force's ballistics section, said he examined a number of items recovered from the scene of the robbery at the Lordship Credit Union in Bellurgan, Co Louth.
These included a green shotgun cartridge found near Det Gda Donohoe's body, which he said was made by a Spanish ammunition manufacturer and was normally used to shoot birds or small animals.
Det Gda O'Donnell told the jury he also carried out test shots to determine the range from which the shot that killed the detective was fired.
Mr Brady denies the murder of Det Gda Donohoe, who was then a member of An Garda Siochana acting in the course of his duty at the credit union on January 25, 2013.
The accused, of New Road, Crossmaglen, Co Armagh, also denies robbery of around €7,000 in cash and assorted cheques from Pat Bellew at the same location on the same date.
Det Gda O'Donnell said he established that the shot impact pattern of the wound to Det Gda Donohoe's right eye was around 60mm in diameter.
He told the court that a gunshot from seven feet gave a shot impact pattern of 64mm, while firing the weapon from six feet gave a shot spread pattern of 52mm.
He agreed with prosecuting counsel Brendan Grehan that, based on these tests, Det Gda Donohoe was struck between six and seven feet from the tip of the shotgun muzzle.
These tests were carried out with a 12-gauge Beretta semi-automatic shotgun, which he said was similar to the weapon that fired the fatal shot.
A 12-gauge Beretta semi-automatic shotgun was then produced in court and made safe by Det Gda O'Donnell before being shown to the jury.
The witness agreed with Mr Grehan that the firearm was being used for illustrative purposes and was not the gun used at the credit union.
The court previously heard the shotgun used in the killing has not been recovered.
Det Gda O'Donnell will continuing giving evidence today.