The woman (31) murdered in Dundalk, Co Louth yesterday was the mother of two children aged 1 year and 6 years.
She was originally from Lithuania and had been living in Dundalk for about 8 years, gardai confirmed.
She died after being stabbed multiple times and a knife was recovered by gardaí.
Gardáí upgraded the inquiry to a murder investigation last night.
It is understood the deceased woman knew the 48-year-old man who was arrested by gardaí on the scene at Bridgewater Mews, Linen Hall Street, Dundalk. It remained sealed off last night.
The deceased woman worked in a shop in the town and was part of a tight-knit community. She could often be seen walking her daughter (6) to the nearby primary school.
It is understood she suffered multiple stab wounds including to the head, chest and legs. She was pronounced dead at Our Lady of Lourdes Hospital, Drogheda yesterday afternoon and a postmortem will be carried out by the deputy State Pathologist today (Wednesday). Efforts were continuing to contact her family in Lithuania.
An incident room has been set up at Dundalk Garda station and gardai have appealed for anyone who has information or who may have witnessed what happened to contact them.
They also asked for anyone who may have dash-cam footage of Linen Hall Street between 2.30pm -2.45pm yesterday to contact them at the incident room on 042-9388400 or the Garda Confidential Line 1800-666111 or any Garda station.
Last night the chairman of Dundalk Municipal District Conor Keelan expressed shock at the murder and said, “I would like to express my immense sympathy to her family. I will be reaching out to the Lithuanian community in Dundalk.”
A man who lives nearby but did not want to be named said: “My wife often saw her walking with her daughter towards school. We are a very quiet community here and everybody is on good terms. This is a shock, this is a quiet area.”
Maria Macostrai who lives 100 metres from the scene said last night, “I feel scared now because you cannot be safe.”