Detectives investigating a murder ambush have arrested three men and a woman.
A car was also seized as part of an ongoing inquiry into Jamie Lindsay's killing in Athy, Co Kildare, last weekend.
The four suspects, all in their early 20s, were detained during a search and arrest operation in both Stradbally and Athy.
They are being questioned at different Garda stations in Co Kildare under Section 50 of the Criminal Justice Act and can be held for up to a week.
Mr Lindsay, 20, and originally from Finglas in Dublin, is believed to have been lured to his death by a text message in the Coneyboro housing estate in Athy, where he lived, last Saturday night.
Gardai are following a number of lines of inquiry, including that he may have been targeted over a drugs row or a personal dispute.
His killer fired a shotgun from a passing car after the victim left his home to walk along or by a nearby lane.