Courts / Dublin / Report

Derek Boyd now a double killer as jury finds him of guilty of murder

Date
2026-07-22

Stage
Sentence

Primary locality
Dublin

County
Dublin

Summary

Derek Boyd was found guilty of murder by a Central Criminal Court jury after fatally stabbing Mark Carroll in his north Dublin home. The prosecution argued that Boyd's actions were not in self-defense, and the jury rejected the defense's claim that Carroll had returned to the house to make peace. Boyd fled to Scotland shortly after the killing and later returned to Ireland to surrender. The court heard that Boyd had previously been convicted of manslaughter for the death of his sister and was on a suspended sentence at the time of the murder. Judge Melanie Greally will sentence Boyd to life imprisonment, with the trial set to continue on July 28. The case also involved Boyd's girlfriend, Chantelle Harcourt, who was accused of obstructing the prosecution. The jury was unable to reach a verdict on the assault charge against Boyd and Harcourt, but they unanimously found Boyd guilty of murder. Chantelle Harcourt pleaded not guilty. Derek Boyd pleaded not guilty.

Who, what, where, when and why

What: Report matter: Derek Boyd now a double killer as jury finds him of guilty of murder. Charges or matters: assault causing harm to his girlfriend Ms Rock in her home, where gardai noted on arrival that she was bruised, bloody-faced and visibly shaking; the manslaughter of his sister Sandra Boyd on October 7, 2022; two offences because he had not been sentenced before his death; assault causing harm to a 36-year old man in 2022, which allegedly occurred on the Phibsborough Road in Dublin 7; assault causing harm to Megan Rock at her home in Ashbourne, Co Meath as well as another offence; murdering Mr Carroll (34) at his home on June 9, 2024. Procedural stage: sentence

When:

March 2022 Hearing Or Sentence
June 9, 2024 Incident
July 28 Adjournment
July 30 Adjournment
June 8, 2024 Incident
June 8 Other
August 2, 2025 Other
August 5, 2025 Other
October 7, 2022 Incident
March 21, 2022 Incident
November 2022 Hearing Or Sentence
December 2022 Hearing Or Sentence
2026-07-22 Publication

Why: She further denied that she had waited three houses down the road because Mark "simply wasn't going back to talk". CNI source report

Case subjects

Chantelle Harcourt

Accused

Charges: assault causing harm to his girlfriend Ms Rock in her home, where gardai noted on arrival that she was bruised, bloody-faced and visibly shaking; the manslaughter of his sister Sandra Boyd on October 7, 2022; two offences because he had not been sentenced before his death; assault causing harm to a 36-year old man in 2022, which allegedly occurred on the Phibsborough Road in Dublin 7; assault causing harm to Megan Rock at her home in Ashbourne, Co Meath as well as another offence (Alleged Or Contested)

Plea: Not guilty

Outcome: The judge will hand down the mandatory sentence of life imprisonment to Boyd on July 28 next and remanded the defendant in custody until that date.

Derek Boyd

Convicted Person

Charges: murdering Mr Carroll (34) at his home on June 9, 2024; assault causing harm to his girlfriend Ms Rock in her home, where gardai noted on arrival that she was bruised, bloody-faced and visibly shaking (Alleged Or Contested)

Plea: Not guilty

Outcome: Derek Boyd, who was serving the suspended part of a sentence for the manslaughter of his sister when he fatally stabbed another man in the chest at his north Dublin home, is now a double killer after being found guilty of murder by a Central Criminal Court jury this afternoon. The judge added: "The position is that you have convicted Derek Boyd on the most serious charge – the murder charge – and he will be sentenced by me very shortly on that.; The judge will hand down the mandatory sentence of life imprisonment to Boyd on July 28 next and remanded the defendant in custody until that date.