Gardaí believe more than 20 shots were fired in the Dublin gangland attack in which a man and a woman were shot dead and three others injured on Wednesday.
The scene of the shooting outside a house on Balbutcher Drive in Ballymun, north Dublin, remained sealed off on Thursday.
Gardaí fear the attack represents an escalation of a feud between rival Ballymun-based factions which has been simmering for about 18 months, although without loss of life.
It is unrelated to the notorious Kinahan-Hutch gangland feud which has claimed several lives.
A significant level of Garda resources is currently being deployed daily to shore up security in areas where Kinahan-Hutch suspects and potential victims live. Senior officers fear some of those resources, including specialist armed teams for checkpoints and anti-gang patrols, will need to be diverted to the Ballymun area following Wednesday’s shootings.
Dublin has had separate gang feuds running simultaneously in the past. But not since 2009-2010 have gardaí had to deal with more than one serious feud at the same time.
The two who died on Wednesday were Antoinette Corbally, a 48-year-old mother of six, and Clinton Shannon, a 30-year-old locksmith with no known involvement in crime who lived in Swords.
Ms Corbally, who lived at the house where the shooting occurred, was a sister of Derek Devoy (37), the gunmen's intended target.
Gunmen
Devoy is a criminal figure who has spent many years in prison. He was at the scene when the gunmen opened fire, killing Ms Corbally and Mr Shannon, who is believed to have driven Devoy to the house. Devoy dropped a child he was carrying into the house and fled to safety on foot.
The attack involved a burst of gunfire from a sub-machine gun, as well as shots from at least one other gun. A member of the extended family, Andrea Corbally (18), who was holding a child inside the house, was injured, though not seriously. A friend of the family Brian Moran, aged in his 50s, was also wounded, but is expected to make a full recovery.
The attack occurred in a busy housing estate where children on summer holidays were playing outside.
Gardaí believe the killers had specific information on Devoy’s movements and had him under surveillance.
Devoy's brother, Michael, was shot dead a day after being released from prison in January, 2014. However, gardaí believe Wednesday's attack was linked to a local feud and was not carried out by the gang that killed Michael Devoy.
A Ballymun-based drugs gang has blamed Derek Devoy for a number of pipe bomb and non-fatal shootings in recent months. It is believed Devoy owns two properties on the road – the one where the shooting took place and another across the street.
Fingertip searches
Around 100 gardaí are involved in the investigation. Neighbours said gardaí were carrying out fingertip searches in every back garden on the street, and conducting repeated door-to-door inquiries.
Balbutcher Drive was reopened to traffic on Thursday, but a cordon remained around the front of the house where the shooting occurred. Several bullet holes could be seen in the glass door at the front and around the door frame.
Other pieces of evidence such as a partially burnt out Opel Zafira and bullet casings have been removed for further examination. The attackers had attempted to burn the car after the shooting but gardaí were able to put out the fire when they arrived at the scene.
