Detectives still investigating string of unsolved cases
Among the unsolved murders this year is the shooting of Dean Johnson (20), who was hit in the head and shoulder as he sat in the back of a friend's car last May.
Investigators have been checking out a number of theories for the motive for the killing including his alleged involvement in an incident at a nightclub the previous weekend.
Officers were also active last week in their inquiries into the murder of Michael Taylor Snr last June, as part of a bigger operation into the activities of two gangs.
Eleven people were arrested during an operation involving more than 150 gardai.
Last June, father-of-four Liam Kenny was shot four times as he tried to prevent a gang breaking into his house in Clondalkin in west Dublin.
Kenny was a prominent member of the Continuity IRA in Dublin but his murder is believed to have been connected to an ongoing row with a drugs gang.
Last June Darren Cogan (22), of Bluebell Avenue, was shot dead in the Black Horse Inn in Inchicore. Gardai are following two main lines of investigation.
One is that he was a victim of mistaken identity while the second suggested he had become caught up in a row that started between two women.
Last month gardai recovered the gun used in his murder during the search of woodland in north Cork.
Father-of-three Tom McDonagh (49) died after he was hit in a blaze of automatic gunfire in his mobile home in Ballymun in September.
Gardai believe Mr McDonagh was targeted over a drugs debt.
A major gangland figure was singled out by rivals in September after a dispute over extortion demands.
Kelly knew there was a "contract" on his head and had been moving between Spain and the Netherlands.
But he flew back here for the birth of his baby son and was gunned down shortly after visiting the infant.