A potential forensic breakthrough has been made by police investigating the murder of 10 workmen in the North 40 years ago.
The IRA was blamed for killing the textile workers outside the Co Armagh village of Kingsmill in January 1976.
The forensic development in the investigation comes only a week after a new inquest into the atrocity began at Belfast Coroner's Court.
It is understood a potential palm print match was discovered during re-examination of evidential material.
Relatives of the victims were informed about the find ahead of the scheduled sitting of the inquest on Tuesday.
The print was found on a suspected getaway vehicle.
Assistant Chief Constable Mark Hamilton, head of the Police Service of Northern Ireland's legacy and justice department, said: "Due to a recent forensic development, detectives from Legacy Investigation Branch are now following a line of inquiry in relation to the murders at Kingsmill in 1976. A senior investigating officer has now been appointed in order to take this forward.
"We have been liaising with the Coroner's Office in relation to this and will continue to do so.
"The families have also been informed. I appreciate this is a very difficult time for them; however, we are committed to progressing this matter as expeditiously as possible and will keep them updated as appropriate."