Forensic evidence was presented to the High Court in Glasgow today (Monday) in the ongoing trial of two men accused of murdering Liam Aitchison and it was confirmed that one of the accused’s blood and DNA had been identified in the room where the body was discovered.

Johnathan Mackinnon and Stefan Millar – both 22 – are accused of murdering the teenager at a house in Steinish on November 23rd 2011.

Forensic Scientist, Sarah Jones from the Scottish Police Authority, who specialises in identifying blood stain patterns, said drops of blood found in the room where Liam’s body was found were identified as a match to Johnathan Mackinnon’s DNA profile.

She said the majority of blood in the room was Liam’s blood but that spots in one area on the carpet were a match to Mr Mackinnon.

Prosecutor Iain McSporran asked if someone had been bleeding from a cut on their hand, could that produce drops of blood like those found in this area? She agreed that was one possible explanation.

She said that Mr Mackinnon’s blood was also found on one of the socks which Liam was wearing with a DNA match to the other sock and also the door handle of the room.

No blood was found outwith the room.

Ms Jones had attended the scene at the Steinish house and carried out chemical testing to identify blood stains and also took samples for further examination in a laboratory in Aberdeen.

In analysing the stains she concluded that some of the blood stains could have come from a person being struck perhaps repeatedly while lying or crouching on the floor. She said there was also blood smearing in one area which indicated contact with a source that was wet with blood. She said they had also found hair in this area.

Prosecutor Iain McSporran asked her if the scene was typical of violent death. She said there was really no such thing as ‘typical’ in crime scenes but commented: “In this particular scene the areas on the carpet were quite saturated and in my mind indicated quite a significant blood loss.”

She said the position of blood staining suggested that the deceased was not assaulted in the position where his body was found but in another part of the room and she said in her view it was feasible that the deceased had moved across the carpet by crawling or crouching or was dragged to his final position.

The blood and damage to the t-shirt Liam was wearing was also examined. All blood on this item of clothing was found to be Liam’s and it was also analysed to have 20 areas of damage to it. Eighteen of those were interpreted as from separate actions involving a sharp edged object and a further two areas of complex cutting which could have been two separate actions.

She said it was not possible to age blood stains so she would not be able to say when blood spots matching Mr Mackinnon’s DNA profile would have been deposited.

In cross examination by defence lawyer Mr Iain Paterson, Ms Jones was asked was it likely that if someone had repeatedly punched or kicked or struck the deceased in the position where the blood smearing was evident, there would have been a transfer of blood? She said this was correct.

He asked: “Would it not be virtually impossible for there not to be a transfer to the person carrying out the assault?”

“Essentially it would be quite surprising not to get a transfer,” she replied.

Mr Paterson pointed out that the person responsible might have carried the rest of Liam’s clothes out of the house, going down the hallway in the dark in an area which contained several items. Ms Jones said those items in the hallway had been examined for traces of blood but none were found.

Pieces of broken glass were also analysed, some of which included blood stains and also hair which had been cut near the root end which could mean the deceased was struck with broken glass.

Cigarette ends found in the property were also tested for DNA but did not offer a match.

Ms Jones said searches of Mr Mackinnon’s home in Plasterfield had included the removal of a large quantity of knives and sharp objects which were tested but none of them were found to have traces of Liam’s blood on them. Items were also taken for testing from Stefan Millar’s home and none were found to have DNA from Liam Aitchison on them.

Both accused deny the charges against them. The trial before Lord Kinclaven continues.