Gardaí investigating the murder of Howth woman Celine Cawley are examining a brick found at the scene of the killing.
Detectives believe the dead woman's head injuries were inflicted by an attacker who beat her severely and used an implement. They believe the brick being examined may have been used during the attack yesterday morning.
A postmortem was carried out today on Ms Cawley, who was found dead at her home in Howth, north Dublin yesterday. State Pathologist Prof Marie Cassidy was due to carry out the postmortem on the dead woman's remains this afternoon.
Gardaí investigating the murder of Ms Cawley are hopeful exhaustive forensic examinations over the coming days on her body and at her house will help solve the case.
Garda sources said the dead woman was involved in a very violent struggle with her killer during which she suffered blunt-force trauma injuries to her head. Gardaí believe the murderer's DNA may be under the dead woman's fingernails and that such evidence will prove vital if a suspect is identified.
Gardaí were alerted to the murder at Windgate Road, Howth Head, just before 10am yesterday after the dead woman's husband, Eamon Lillis, phoned for an ambulance for his wife.
He has told gardaí that when he returned home from leaving his 16-year-old daughter to school and then walking his dogs, he interrupted a masked man who had already beaten his wife.
He has also told investigating officers that, while he tackled the masked man, the man ran down the back garden of the house, on to the Carrickbrack Road area, and escaped still wearing a balaclava.
When uniformed gardaí arrived at the address on the southern slopes of Howth Head just after 10am, they found Ms Cawley in her night clothes lying unconscious on the patio at the rear of the substantial property.
She was taken by ambulance to Beaumont hospital where she was pronounced dead. Mr Lillis had a number of marks on his head from his fight with the intruder.
The Irish Timesunderstands there were no signs of a break-in and nothing appears to be missing.
Ms Cawley was the founder and managing director of Toytown Films, a successful independent television company producing adverts for major global brands since 1990. Mr Lillis is a producer with the company. While shocked, he was in a position yesterday to speak at length to gardaí about the intruder he saw.
According to Supt John Gilligan, head of the Garda Press Office, the intruder is described as being in his late 20s or early 30s and of slight but strong build. "We're keeping a very open mind on the situation and are just trying to gather as much information as possible," Supt Gilligan said.
Gardaí have appealed for anybody who was in the Windgate Road-Carrickbrack Road area at about 10am yesterday to come forward.
A large area around Howth Summit, close to the murder scene, was sealed off for forensic examination yesterday.
CCTV footage from cameras at houses around the murder scene is also being collected by gardaí.