THE suspected killer of body-inthe- Saab mum Helen Donegan had been planning to bury her remains in a shallow grave.
Helen was blasted in the chest but the suspect has told gardai the killing was an accident.
At one stage, the suspect told officers he was trying to take his own life but the blast caught the victim. Detectives have established the suspect had recently transferred her badly decomposed corpse from another car to the Saab estate.
And it is understood the plan had been to dispose of the body in a secret grave.
The Herald revealed last night how the suspect handed in the weapon used in the killing on the day Ms Donegan went missing.
In the normal course of events the weapon would have been destroyed because its licence had expired.
However, gardai became suspicious of the man's motivation and retained the shotgun.
Officers investigating the shooting continued to question a businessman today.
It is understood the suspect in the case claims he shot her by mistake, while he was trying to commit suicide.
The alleged killer says that Helen, who was a drug addict, got between him and the weapon as he attempted to shoot himself on May 6.
He claims her death was totally accidental.
Officers believe the 30-year-old mum was shot dead shortly after she went missing from her rented home in St Patrick's Park, Celbridge, Co Kildare, on May 6.
A post-mortem examination by state pathologist Dr Marie Cassidy confirmed she died from a single shotgun blast to the chest.
Ms Donegan, originally from Ballyfermot, was reported missing to gardai on May 17, 11 days after her disappearance.
Around the same time -- as reported in the Herald -- the suspect had given the murder weapon to gardai, hoping it would be destroyed.
Forensic tests were being carried out by experts to establish if the recovered gun was the murder weapon.
It is believed that, shortly after Ms Donegan, who has a 12-year-old son, was murdered, her body was placed in the boot of a blue Seat estate car.
The car was then parked in the driveway of a house and subsequently returned to its original location.
The body was then transferred to the boot of a 02D silver grey Saab estate, where it was found by gardai.
They had been searching a rented garage at Kilmactalway, Aylmer Road, Newcastle, Co Dublin, when they became suspicious about the boot of the Saab.
The remains have not yet been officially identified.
Gardai will be relying on DNA evidence and dental records to confirm they belong to Ms Donegan.
Her family in Ballyfermot and in Co Clare were notified of the discovery of the body and have been kept fully briefed.
Gardai have issued an appeal to anybody with information about suspicious activity around Ms Donegan's home or the garage where the body was found to contact them on 01-6667600.