Gardaí have issued a further appeal for information in relation to the murders of Antoinette Corbally and Clinton Shannon.
Ms Corbally, a 48-year-old mother of six, and Mr Shannon, a 30-year-old locksmith with no known involvement in crime who lived in Swords, were gunned down at Balbutcher Drive in Ballymun last week.
Ms Corbally, who lived at the house where the shooting occurred, was a sister of Derek Devoy (37), the gunmen's intended target.
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.
The feud is unrelated to the Kinahan-Hutch gangland feud which has claimed several lives.
On Friday, gardaí made a further appeal to members of the public who may have vital information to assist them in their investigation.
Det Supt Colm Fox, who is heading up the investigation on the case thanked the Ballymun community for their assistance to date in the case and made an appeal in relation to two cars of interest in the investigation, a silver Opel Zafira and a black VW Golf.
Cars used
"The first of these cars is a silver Opel Zafira registration number 08-LS-3101. Prior to the murders, this car was parked beside a building site at the junction of Balbutcher Lane and Balbutcher Drive, Ballymun for at least an hour.
“From this vantage point the occupants had a clear view of the location where the murders took place. When the intended target of the gunmen drove into Balbutcher Drive, the Opel Zafira car lefts its vantage point and followed the intended target to the location of the murders.”
“The intended target escaped injury however two innocent persons were murdered and two others were injured,” added Mr Fox.
Gardaí believe that the occupants of the silver Opel car fled the scene on foot through bollards at the end of Balbutcher Drive onto Crannoge Terrace.
"A black Golf registration number 06-LH-3466 was waiting for them here and drove them away. It travelled across Ballymun in the direction of Ikea, on through the Northwood business, retail and housing development and on into Santry Close where it was set on fire," he said.
Mr Fox said that gardaí believed the cars were purchased in the weeks preceding the murders and had to have been parked up somewhere.
He appealed to members of the public to contact them if they saw these, or similar type cars parked anywhere.
Gardaí are appealing for witnesses or anyone with any information to contact them at Ballymun Garda Station on 01-6664400, the Garda confidential line 1800 666 111 or by e-mail: Ballymun_Incident_Room@garda.ie