More than 150 cold case murders, mainly gangland and in Dublin, over the past two decades remain officially unsolved after a massive review brought little in the way of substantial progress.
The review began under the direction of then Deputy Commissioner and now Commissioner Noirin O'Sullivan in 2013.
Gardai have substantial suspicions and intelligence about those who carried out the murders, but little has progressed since the early days of each investigation. The average conviction rate in Dublin gang-related murders is less than one in 10.
The Garda Western Division in Dublin, which covers the area from Finglas and Coolock in the north, to Clondalkin, Lucan and Ballyfermot in the south, has the largest number of unsolved murders in the State, with just over 70 gang killings remaining unsolved.
The Dublin Metropolitan Area Northern Division, which covers the area from the north inner city to the northern suburbs, remains the second worst in terms of convictions for gang-related murders. Only one out of around 30 gangland murder cases has been solved. Two divisions - Central and Southern Dublin - account for the remainder of unsolved gang murders.
The Dublin Eastern Division, with its headquarters in Dun Laoghaire, remains the only city division with no gang-related murders. As part of the review, detectives in Dun Laoghiare re-examined the September 1999 murder of 17-year-old Raonaid Murray but there does not appear to have been any significant advances in this case.
The pattern of gang killings is continuing this year with three gun murders in the Garda Western Division, two in the Southern Division and one in the Northern.
Gardai are also still examining the disappearance and believed murder of Anna Varshavne (20) and her boyfriend Willie Maughan (34) north of Dublin in Co Meath. It is believed they were murdered by members of a Traveller drugs gang who secretly buried their bodies. They were last seen alive on April 14.
Mr Maughan, who was said to have had a drug problem but had been 'clean' in recent years, was believed to be killed by the gang who control much of the opiate trade in the area north and west of Dublin. It is believed the couple were murdered because Mr Maughan was aware of details of a previous murder by the same gang.
Finglas has some 30 gang murders remaining on the garda books. The 'clearance' rate for gang-related murders in Ireland lags behind forces in other European jurisdictions.