A 51-year-old man is still being questioned in connection with the investigation into the murder of Miriam Burns at her home in Killarney, Co Kerry.
Questioning at Killarney Garda Station got under way shortly after 7am.
The man can be held for up to 24 hours with rest breaks.
Gardaí also carried out a search at two locations on the Ross Road of the town.
Meanwhile, door-to-door inquiries are continuing on the Ardshanavooley estate where Ms Burns' home remains preserved as a crime scene.
Last evening, Assistant State Pathologist Dr Margot Bolster visited the terraced house close to the town centre after gardaí upgraded their investigation to a murder inquiry on foot of her post-mortem examination findings.
Gardaí are appealing for witnesses and/or dashcam footage from anyone who may have been in the Ardshanavooly area between 5pm last Friday and 1pm on Monday to contact them at the incident room at Killarney Garda Station.