Courts / Dublin / Report

'He told me 'I'll stick the knife up your h*le': Derek Boyd takes stand at own murder trial

Date
2026-07-16

Stage
Trial

Primary locality
Dublin

County
Dublin

Summary

Derek Boyd, 31, took the stand at his murder trial before Ms Justice Melanie Greally. He admitted to previously pleading guilty to his sister's manslaughter and stated he was serving part of that suspended sentence when the incident occurred. Boyd pleaded not guilty to murdering Mark Carroll, 34, at his home in Finglas on June 9, 2024, and to assaulting Megan Rock. His partner, Chantelle Harcourt, 34, pleaded not guilty to impeding the apprehension of the offender. Boyd testified that he picked up a knife to deter Carroll, who he alleged threatened to kill him, and swung it during a struggle without intent to injure. Prosecution counsel Sean Guerin SC cross-examined Boyd on his prior firearm-related manslaughter conviction and alleged he exaggerated Carroll's threats. The judge directed a not guilty verdict on the count of threatening to kill Megan Rock due to insufficient evidence. The trial continues tomorrow.

Who, what, where, when and why

What: Report matter: 'He told me 'I'll stick the knife up your h*le': Derek Boyd takes stand at own murder trial. Charges or matters: his sister's manslaughter and was serving part of that suspended sentence when the incident happened with Mark Carroll; murdering Mark Carroll (34) at his home on June 9, 2024. Procedural stage: trial

When:

June 8, 2024 Incident
June 9 Other
June 9, 2024 Incident
2026-07-16 Publication

Why: Mr Boyd said he had done this because he had been through a tragic incident and that he would "hardly set out to do another". CNI source report

Case subjects

Chantelle Harcourt

Defendant

Plea: Not guilty

Derek Boyd

Accused

Charges: his sister's manslaughter and was serving part of that suspended sentence when the incident happened with Mark Carroll; murdering Mark Carroll (34) at his home on June 9, 2024 (Admitted)

Plea: Guilty