'Mary told me she had affair with Quirke - and now he was stalking her'
Ex-police officer's notes recounting killer's frightening behaviour not used in case
Patrick Quirke exhibited a litany of stalker-like behaviours towards his former lover after she dumped him, it has emerged.
Retired Scotland Yard police officer Catherine Costello recalled a series of unsettling incidents concerning convicted murderer Patrick Quirke and his treatment of his former lover, widow Mary Lowry.
"She had taken the kids to school and when she arrived back he was sitting at the kitchen table. She asked him, 'How did you get in?' He said: 'You left the door unlocked.'
"She was convinced she had locked the door. To steal keys, to intrude in your house, to frighten you, to stage break-ins, this is not somebody in love with you - it's not normal," she said.
Her comments feature in the documentary 'Mr Moonlight: The Trial of Patrick Quirke', airing tonight at 10pm on Virgin Media One.
Ms Costello is co-founder of the Searching for the Missing group.
She took part in the search for the truck driver and part-time DJ Bobby Ryan - known as Mr Moonlight - whose body was found in a disused tank on Mary Lowry's farm 22 months after he disappeared on June 3, 2011.
Contemporaneous notes taken by her and reported in yesterday's 'Sunday Independent' reveal Ms Lowry was concerned that the now convicted murderer was stalking her after she ended what she termed "a seedy affair" with the married dairy farmer.
Her notes, which were not admitted as evidence during the mammoth 15-week trial as they were deemed to be hearsay, reveal that Mr Ryan (52) had warned Quirke (50) to stay away from Ms Lowry and confronted him about it. In her statement to gardaí, Ms Costello said: "Bobby Ryan had been aware of that affair as Mary told him. Mary Lowry told me that Bobby had told Quirke to stay away from her as Quirke had made her life extremely uncomfortable."
In her notes, Ms Costello revealed that in her third meeting with Ms Lowry, the mother of three disclosed her affair with Quirke while sobbing and exhibiting "absolute hysteria to the point hyperventilating".
She had prefaced her admission of the affair by stating: "I'll tell you why I think he did something to Bobby."
The notes also describe Ms Lowry's disturbing account of how she came home one night to find that someone had broken into her home through the bathroom window, yet nothing was missing.
Her notes quoted Ms Lowry as telling her: "I think it was Pat Quirke that did it because I had an affair with him and he's been stalking me."
The notes recalled another unsettling incident the following day in which she came home to find Quirke sitting at her kitchen table even though Ms Lowry was convinced she had locked the door after the previous break-in.
Ms Costello then told Ms Lowry not to "beat herself up" over the affair with Quirke.
"Mary, Mary, listen, will you do me a favour? Stop beating yourself up. Brothers-in-law do not do this. You have to stop beating yourself up," the notes said in reference to Quirke's menacing behaviour.
"I also told Mary, 'this isn't love. Don't be fooling yourself he is in love with you. This isn't love'."
Sources told the 'Sunday Independent' that gardaí also believed Quirke had been stalking Ms Lowry following the demise of the affair.
A senior source said investigators believed Quirke had planted a voice-activated recording device in Ms Lowry's home in order to spy on her. They also believe the device, which was never found, may have been used in the planning of Mr Ryan's murder. However, four audio recordings - including three 'sex tapes' - were recovered on Quirke's computer.
One of the three tapes that recorded a couple having sex was confirmed by Ms Lowry as being of her and Quirke.
A fourth tape was a recording of Ms Lowry and her subsequent boyfriend Flor Cantillon reading out an agony aunt column from the 'Sunday World'.
Ms Costello's notes also reveal that following Ms Lowry's emotional admission of the affair, she suspected the case was no longer one of a missing person but of murder.
For that reason, she urged Ms Lowry to tell gardaí about the affair with Quirke as soon as possible.