# Limerick man awaits sentencing for indecent assault of third victim Case 2048. Sexual assault, indecent assault, Co. Limerick **TL;DR:** Christopher O'Mahony (68), of Kerrykyle, Ardagh, County Limerick, sexually abused his daughter Emma O'Shaughnessy, now 42, from 1993 to 1996 when she was aged 10 to 13, and his sister-in-law Helen Costelloe, now 51, from 1983 to 1989 when she was aged between nine and 15. The abuse emerged after a family meeting on 4 July 2021 when Ms Costelloe disclosed it and Ms O'Shaughnessy said she had also been abused, and O'Mahony presented himself at Henry Street Garda Station with his wife three days later and admitted it. He pleaded guilty to 18 sample counts of sexual and indecent assault from 54 on the indictment and was jailed for nine years by Judge Sinead McMullan at Limerick Circuit Criminal Court on 20 March 2025, and placed on the sex offenders register. In November 2026, a third victim who contacted gardai after reading reports of the case came forward, and O'Mahony pleaded guilty at Limerick Circuit Criminal Court to two counts of indecently assaulting her on two dates in the 1970s when she was aged between five and 12, with sentencing due on 19 November 2026. **Stage:** Sentenced. Reported stages: In court (2026-11-12), Convicted (2025-03-18), Sentenced (2025-03-20) ## People - Victim: Emma O'Shaughnessy, woman, 42 - Victim: Helen Costelloe, woman, 51 - Suspect: Christopher O'Mahony, man, 68 ## Key facts **What happened** - Christopher O'Mahony sexually and indecently assaulted his daughter Emma O'Shaughnessy and his sister-in-law Helen Costelloe when they were children, including assaulting Ms O'Shaughnessy in the family bathroom under the pretext of applying acne cream and forcing himself on Ms Costelloe in a public toilet in Glin in 1987 and in his car on work rounds. - O'Mahony has also admitted indecently assaulting a third victim, a young girl, on two dates in the 1970s when she was aged between five and 12. **Where** - The abuse of Ms Costelloe occurred in locations including the family home in Ballyhahill, O'Mahony's home in Ardagh, the old dispensary in Ballyhahill and the health centre in Glin, and O'Mahony is of Kerrykyle, Ardagh, County Limerick. **When** - The abuse of Helen Costelloe ran from 1983, when she was nine, until 1989, and the abuse of Emma O'Shaughnessy from 1993, when she was 10, until 1996, when she was 13 and fought back. - The abuse emerged after a family meeting on 4 July 2021 at which Helen Costelloe disclosed she had been abused and Emma O'Shaughnessy said she had also been abused. **Investigation** - On 7 July 2021, three days after the family meeting, O'Mahony presented himself at Henry Street Garda Station with his wife and admitted the abuse, with Detective Garda James Muldowney of the Limerick Garda Divisional Protective Services Unit leading the investigation. - The third victim contacted gardai after reading media court reports about O'Mahony abusing his daughter and sister-in-law, and Detective Garda James Muldowney visited O'Mahony at Midlands Prison to put the fresh allegations to him. **Charges** - O'Mahony was charged with 54 counts on indictment and pleaded guilty to 18 sample counts of sexually and indecently assaulting the two girls, reported as 10 or 11 sample indecent assaults on his sister-in-law and seven sample sexual assault counts on his daughter. - O'Mahony pleaded guilty to two counts of indecently assaulting the third victim on two dates in the 1970s. **In court** - The case was heard at Limerick Circuit Criminal Court before Judge Sinead McMullan, who lifted a reporting ban on O'Mahony's name after the victims waived their anonymity. **Sentence** - On 20 March 2025, Judge Sinead McMullan jailed O'Mahony for a total of nine years for sexually assaulting his daughter and sister-in-law. - O'Mahony was placed on the sex offenders register, reported as for life, and was remanded in custody to be sentenced for the 1970s indecent assaults on 19 November 2026. **Other details** - O'Mahony, a former rates collector with Limerick County Council, also beat and psychologically abused his daughter, controlling when she could go to the toilet and how much toilet paper she could use, causing urinary tract infections, and warned the children not to talk about the abuse. - The emergence of the abuse caused a split in the family, Ms O'Shaughnessy said her mother and two sisters supported her abuser, Ms Costelloe waited three years on a waiting list to see a counsellor after contacting a rape crisis centre, and a letter of apology from O'Mahony was handed in to the judge. ## Reports (9) | Date | Outlet | Report | |---|---|---| | 2025-03-18 | limerickleader.ie | [Controlling 'monster' sexually abused daughter and sister-in-law and rationed toilet paper, Limerick court hears](https://www.limerickleader.ie/news/controlling-monster-sexually-abused-daughter-and-sister-in-law-and-rationed-toilet-paper-limerick-court-hears-6885710) | | 2025-03-18 | limerickpost.ie | [Limerick man unmasked as ‘monster’ who sexually abused daughter and sister-in-law](https://www.limerickpost.ie/2025/03/18/limerick-man-unmasked-as-monster-who-sexually-abused-daughter-and-sister-in-law/) | | 2025-03-19 | limerickleader.ie | [‘Civil war’ breaks out in Limerick family after victims reveal ‘secret’ of sexual abuse](https://www.limerickleader.ie/news/civil-war-breaks-out-in-limerick-family-after-victims-reveal-secret-of-sexual-abuse-6884422) | | 2025-03-20 | irishtimes.com | [‘Monster’ jailed for nine years for sexually abusing daughter and sister-in-law](https://www.irishtimes.com/crime-law/courts/2025/03/20/monster-jailed-for-nine-years-for-sexually-abusing-daughter-and-sister-in-law/) | | 2025-03-20 | thejournal.ie | [Man jailed for nine years for sexually abusing daughter and sister-in-law](https://www.thejournal.ie/man-jailed-for-nine-years-for-sexually-abusing-daughter-and-sister-in-law-6655302-Mar2025/) | | 2025-03-20 | irishmirror.ie | ['Monster, paedophile' dad jailed as victims of horrific abuse speak out](https://www.irishmirror.ie/news/irish-news/monster-paedophile-dad-jailed-9-34903197) | | 2025-03-21 | limerickpost.ie | [‘Monster’ and 'paedophile' father jailed for nine years for sex abuse of daughter and sister-in-law](https://www.limerickpost.ie/2025/03/21/monster-and-paedophile-father-jailed-for-nine-years-for-sex-abuse-of-daughter-and-sister-in-law/) | | 2025-03-21 | limerickleader.ie | [BREAKING: Limerick 'paedophile' and 'monster' jailed for sexually abusing daughter and sister-in-law](https://www.limerickleader.ie/news/breaking-limerick-paedophile-and-monster-jailed-for-sexually-abusing-daughter-and-sister-in-law-6884020) | | 2026-11-12 | limerickpost.ie | [‘Monster’ paedophile facing more jail time after third victim comes forward](https://www.limerickpost.ie/2026/11/12/monster-paedophile-facing-more-jail-time-after-third-victim-comes-forward/) | HTML: https://irelandcrime.com/case/limerick-man-awaits-sentencing-for-indecent-assault-of-third-victim-2048 This page is put together automatically from the reports listed above. 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