GARDAÍ investigating the murder of Celine Cawley in Howth, north Dublin, are examining the clothes she was wearing when she was killed.
Gardaí are seeking to identify a masked intruder, with whom her husband Eamon Lillis (50) said he had fought on entering their home after the attack.
Mr Lillis said he found an intruder attacking his 46-year-old wife at their home on Windgate Road, Howth Head, at 10am on Monday.
Gardaí have also taken clothes worn by Mr Lillis in the hope that it might help them identify the intruder.
Detectives are working on a definite line of inquiry.
They are hopeful an examination of the clothing worn by the dead woman and Mr Lillis, both of whom struggled with the intruder, will yield substantial DNA evidence.
The clothing is among a number of items that were taken from the house for examination. The testing process on those items and samples taken from Ms Cawley's remains will take some time. However, gardaí believe the line of inquiry they are exploring will be conclusively strengthened or discounted on the basis of the DNA and forensic examinations.
Officers stressed that while one line of inquiry has emerged they are still keeping an open mind. They are seeking the public's assistance in tracing the intruder Mr Lillis disturbed at the house on returning home on Monday morning after taking his 16-year-old daughter to school and walking the dogs.
Mr Lillis has been in a position to talk to gardaí.
He has told them that after he grappled with the intruder the masked man ran down the back garden of the family home into a laneway leading towards Carrickbrack Road. The laneway remained sealed off yesterday.
A major search operation of the laneways, roads, fields and gardens around the summit of Howth was still under way yesterday. Gardaí are looking for the intruder's balaclava or any other item that may have been discarded by the killer.
Roads around the summit remained sealed off last night with access being granted to local people only.
Gardaí have already taken a bloodstained brick from the murder scene.
It was found on the back patio where Ms Cawley, a leading commercial television producer, was beaten to death.
Testing on the brick will take some time but gardaí are satisfied it is the murder weapon.
The postmortem on Ms Cawley was completed on Tuesday evening.
State Pathologist Prof Marie Cassidy's examination concluded Ms Cawley died of head injuries consistent with being hit several times by an object.
The house where the killing took place has undergone a major forensic examination in recent days and gardaí are hopeful the results of those tests will help them build a clear picture of the full circumstances around the murder.
The team investigating the case is based at Clontarf Garda station.
As well as local gardaí and the Garda Technical Bureau it also involves members of the National Bureau of Criminal Investigation, the force's serious crimes squad.