A man was in custody in a Dublin Garda station last night, being questioned about the death of a woman in the city centre earlier this week.
Gardaí last night named the woman as Rosemary Dowling of Home Villas, Donnybrook.
The suspect, who is in his 50s, is understood to have presented himself to gardaí.
He was being held at Harcourt Terrace Garda station under the Criminal Justice Act and can be questioned for up to 12 hours.
Gardaí were keeping vigil outside the second-hand book and record store the Ms Dowling managed.
The small premises on Aungier Street, Star CDs, is only yards from Mercer Street where her badly beaten body was found, naked and wrapped in a duvet cover, early on Tuesday.
The shop's failure to open since Monday aroused suspicion locally and led to a breakthrough in the case.
While the area where the body was found remained cordoned off yesterday, detectives searched a separate area of Mercer Street flats which they believe could be the murder scene.
Outside Star CDs, locals expressed shock and sadness at the death of Ms Dowling, a mother of two who was known to most people in the area and who was deeply popular.
Residents said they believed her daughters, aged 13 and eight, were being raised by a sister but had visited their mother regularly.
Kathleen Clarke, from nearby Clover Court, said that while the shop opened at different hours, sometimes not until the middle of the afternoon, it was unusual to see it closed on consecutive days this week.
She recalled a "very friendly" woman, who was well known in the area.
Ms Clarke's daughter, Stephanie, said the woman was "gorgeous" and "always giving me free things".
A regular customer, Martin Lacey, said he bought second-hand books in the small shop, where they were piled so high he would be afraid of causing a collapse.
"She always said she was going to tidy the place up," Mr Lacey said.
Two elderly sisters, originally from Limerick and now living in Cabra, sprinkled holy water on the footpath at Mercer Street where the body was found.
Katie and Brigid McKeogh said they knew the dead woman from their frequent visits to Whitefriar Street Church, opposite the shop. They said she was a lovely person and were saddened by her death.
The manageress of the coffee shop attached to the church said the woman was a frequent visitor, for coffee and to use the facilities.
"She was very friendly," she added.
