Preliminary post-mortem results show the 64-year-old woman who was shot in her home in Tallaght yesterday died from a single gunshot wound to the chest.
Joan Casey was shot by two armed and masked men in her home in Avonbeg Park shortly before 6.30 a.m. yesterday morning.
It is believed the mother of five may have been the mistaken victim of a gangland shooting.
Gardai confirmed today they did not believe the victim, her husband or her brother, who were also in the house at the time, were the intended targets of her attackers.
Neighbours saw the two men fleeing the house on foot after hearing shots. There was no indication the killers had a getaway vehicle.
Gardai and a local ambulance crew were on the scene within minutes of the shooting but the attackers had escaped. Mrs Casey died at the scene.
The Minister for Justice, Mr McDowell, was urged today to set up a specialist Garda unit to combat gangland killers following Mrs Casey's murder.
Labour Party justice spokesman Mr Joe Costello said criminal gangs had "gotten completely out of control", with mercenaries being hired to carry out killings around the State.
He said: "Hardly a week goes by without someone being murdered and now it is not just confined to cities like Dublin, Cork or Limerick but is also happening in the smaller provincial towns and cities.
"This murder has been a terrible shock because it does appear to have been a gangland shooting gone wrong which claimed the life of a good person.
"A large number of gangland killings are being carried out now by mercenary individuals and there is an increasing number of them happening in this country.
"The minister must target the individuals and gangs behind these murders by setting up a specialist Garda gangland unit."
Neighbours were mystified by the killing, describing her as a "living saint" and dedicated worker for her local Catholic church, St Dominic's.
The night before her murder, she had been collecting for the parish lottery to raise funds for the church.
Sinn Féin TD Mr Sean Crowe said the incident highlighted "the lack of police resources" in Tallaght.
Fianna Fáil TD Mr Charlie O'Connor and Fine Gael justice spokesman Mr Jim O'Keeffe also condemned the incident.