An eighth person has been arrested over the murder of a young man and his new girlfriend at the weekend.
Four men and four women are being questioned over the double killing of known criminal Des Kelly, 23, and Breda Waters, 28, on a housing estate in Limerick's Southill area.
Two men are believed to have carried out the murders.
Seven people were arrested yesterday and another woman, in her mid-30s, was detained in the city today under Section 30 of the Offences Against the State Act.
It is believed the attackers called at the house at Castle Oaks View in the troubled O'Malley Park, where Kelly lived with his mother, at around 9am on Sunday.
They were allowed into the house through the back door where Kelly, a father of three young children, was shot at least once in the head at close range with a handgun.
The gangsters then went after Ms Waters, who also had three children and had started dating Kelly only recently, and shot her in the head in an upstairs bedroom.
Kelly's sister and his two-month-old baby were in the house at the time but it is thought the gunmen did not realise anyone else was there.
It is believed Kelly might have fallen out with drug gangs over unpaid debts or missing drugs.
All eight suspects can be held for a total of seven days.