A murder trial has been told there is "moderate support" to contend that the alleged gunman filmed on CCTV is the same man on trial for the killing.
Kieran McLaughlin, from Elaghmore Park in Derry, denies murdering Barry McCrory, who was shot dead in the city in October 2013.
A forensic imagery analyst gave evidence on day five of the trial.
He was asked to compare an image of the accused with a man captured on CCTV at Mr McCrory's flat on the day he died.
Referred to in the trial as 'Man X', the suspected gunman was filmed entering the block of flats at Shipquay Street both before and after the fatal shooting.The court heard that many of Man X's facial features were obscured in the still image that was examined, as the gunman was wearing a hood and safety glasses.
This, the court heard, meant features such as Man X's ears, forehead, eyebrows and hairline were obscured.
The expert said that despite several of Man X's features being obscured, there were some similar features between the two images.
These included a "broad consistency" in the appearance of the noses and the roundness of the chins.
When asked to give his conclusion, the facial comparison expert said that based on his findings "the analysis lends moderate support to the contention that Man X and Mr McLaughlin are the same person."
Under cross-examination by defence barrister the expert admitted his findings were not validated or verified by a colleague or anyone else in the field of facial mapping.