A man shot on farmland in Co Dublin was in critical condition in hospital on Tuesday night as the suspect for the shooting was being questioned by detectives.
The injured man was on life support in the intensive care unit at Tallaght University Hospital amid fears he may not survive.
A business owner in his 50s was arrested after the incident.
The injured man, who is in his mid-30s, has a number of children and is from Tallaght, was shot at about 1pm on farmland close to Mount Seskin, off the Blessington Road, south of Tallaght, as he was out walking with his dog. He was with at least one other man at the time.
Gardaí believe the men came across another man on the privately owned land in the foothills of the Dublin Mountains, when a number of shots were discharged.
Gardaí are trying to establish if initial warning shots were fired in the direction of the dog before the man was shot in the head.
Detectives do not believe the shooting is in any way linked to organised crime. The man suspected of firing the gun, believed to be a handgun, was still at the scene when gardaí arrived. A legally held firearm was recovered for ballistics examination.
Gardaí were trying to establish if the initial altercation arose over the men being on privately owned farmland with the dog before the incident escalated.
The emergency services were contacted immediately after the shooting occurred, with gardaí and paramedics rushing to the scene. The injured man was treated at the scene by paramedics before being taken to hospital.
The scene was sealed off and underwent examination by members of the Garda Technical Bureau.
The arrested man was taken to Tallaght Garda station for questioning where he was still being detained on Tuesday night under section 30 of the Offences Against the State Act, which allows for an arrested person to be questioned for up to 72 hours without charge.
In a statement, gardaí said they were “appealing for anyone with information who may have been in the Hazelgrove area of Tallaght to come forward”. The statement said the injured man had “received an apparent gunshot wound” and was in “critical condition”.