Two people are still being questioned in connection with the murder of Latvian woman Baiba Saulite.
Four people, two men and two women, were arrested in Dublin yesterday morning and were brought to separate garda stations around the city for questioning.
The two women, both aged 20, have since been released and a file will be prepared for the DPP.
The men, a 19-year-old and a 23-year-old, are still being held at Swords and Coolock Garda Stations.
The mother of two was shot dead at her home in Holywell, Swords in Co Dublin on 19 November last year.
