Gardaí are trying to determine whether a motorist who apparently lost control of his car, and hit three pedestrians, was under the influence of any intoxicant at the time.
The driver of the vehicle, a man in his 30s, may have been impaired behind the wheel due to prescription medications he had been taking.
However, Garda sources said that was just one line of inquiry being examined. The man was arrested close to the scene, in a pub car park.
While the incident appears to have been accidental, a criminal investigation into the incident has begun.
If it is confirmed prescription drugs were a factor, the type of medicines involved would dictate the nature of the Garda inquiry.
A number of prescription drugs, such as strong painkillers, are intoxicants under the law in the same way alcohol or illicit drugs are.
Gardaí are investigating not only the man’s driving but his leaving the scene after the incident, which unfolded over a long stretch of road.
One of the three people the driver hit has been left seriously injured in hospital.
Mounted footpath
The incident, during which the driver mounted the footpath in his car, occurred at Coolmine Road, Coolmine, west Dublin, at about 9.30am on Tuesday.
Gardaí said they were appealing to anyone who was in the area and may have seen the Seat Leon car, or any part of the collisions, to come forward and assist the inquiry being conducted from Blanchardstown station.
“At approximately 9.30am gardaí were called to the scene of the incident at Coolmine road at near the train station,” a Garda statement said.
“Two male pedestrians aged 54 and 19 were seriously injured when they were struck by a car. A female pedestrian also sustained minor injuries.”
The injured pedestrians were taken by ambulance to Connolly Hospital.
The teenager was the most seriously injured and there were concerns for his condition on Tuesday night. The woman involved was treated for shock.
Gardaí confirmed the driver failed to remain at the scene but during a follow-up operation gardaí arrested a man in his late 30s a short time later.
He was questioned under Section 4 of the Criminal Justice Act at Blanchardstown Garda station.
“The road is currently closed for technical examination and local diversions are in place,” the Garda statement added.
“Garda Forensic Collision Investigators have been requested to examine the scene. Rail services at Coolmine Station are not affected.”
The car the man was driving was taken by the Garda for analysis.