A 60-year-old man is being questioned about the murder of Jean Eagers in Dublin nine days ago.
The 57-year-old mother-of-two died after she was attacked at her home in Willow Wood Grove in Hartstown last Sunday week.
A man was arrested at the scene after gardaí forced their way into the house but he was taken to hospital for treatment for injuries.
He was discharged earlier today and taken to Blanchardstown Garda Station where he is being detained under Section 4 of the Criminal Justice Act.
He can be questioned for a total of 24 hours.
A number of weapons, including a samurai sword discovered at the scene last week, are being forensically examined.