Wednesday 28 October 2026Compiled from published reports. Every claim links to its source.

Ireland Crime

Every case followed from the first report to the sentence, or to where the reporting stopped.

Case No. 3509Murder · Co. Roscommon · 17 Jun 2020

Stephen Silver appeals murder conviction for killing Garda Colm Horkan in Castlerea

Stephen Silver, 49, appealed his murder conviction for shooting Garda Colm Horkan 11 times with the garda's own gun in Castlerea, Co Roscommon, on 17 June 2020, arguing that the State's psychiatric evidence contradicted the legal test for insanity. The Court of Appeal, presided over by Mr Justice John Edwards, reserved judgment.

  1. Reportednot reported
  2. Arrestednot reported
  3. Chargednot reported
  4. In court19 Mar
    2 reports
  5. Verdict
  6. Sentenced
reportedhappened, not reportedlatest stagenot yet

Key facts

consolidated from all reports
34 statements extracted from the articles
  • whatStephen Silver fatally shot Garda Colm Horkan (irishtimes.com)
  • whatHorkan was shot 11 times with his own gun (irishtimes.com)
  • whatHorkan was an acting detective (irishtimes.com)
  • whatSilver is a 49-year-old motorbike mechanic from Aughaward, Foxford, Co Mayo (irishtimes.com)
  • whatSilver has a long history of bipolar affective disorder (irishtimes.com)
  • whatSilver was hospitalised on psychiatric wards on numerous occasions (irishtimes.com)
  • whatFollowing each admission Silver would stop taking his medication causing relapse (irishtimes.com)
  • whatSilver shot and murdered Garda Colm Horkan after taking the garda's own gun from its holster. (irishmirror.ie)
  • whatSilver is 49, a motorbike mechanic from Aughaward, Foxford, Co Mayo. (irishmirror.ie)
  • whatGda Horkan died having been shot eleven times with his own gun. (irishmirror.ie)
  • whatSilver had a long history of bipolar affective disorder requiring hospitalisation on psychiatric wards on numerous occasions. (irishmirror.ie)
  • whatFollowing each admission, Silver would stop taking his medication, causing him to relapse and be readmitted. (irishmirror.ie)
  • whatOn the night of his death, Horkan responded to complaints from residents after Silver had started blaring music while driving his motorcycle dangerously and burning out his back tyre. (irishmirror.ie)
  • whatCCTV evidence suggested Silver spat in the garda car window, prompting Horkan to get out of the car. (irishmirror.ie)
  • whereThe shooting took place in Castlerea, Co Roscommon (irishtimes.com, irishmirror.ie)
  • whenThe shooting occurred on 17 June 2020 (irishtimes.com)
  • chargeSilver pleaded not guilty to the murder of Det Gda Horkan knowing or being reckless as to whether he was a member of An Garda Siochana acting in the course of his duty. (irishmirror.ie)
  • courtSilver pleaded not guilty to the murder of Horkan (irishtimes.com)
  • courtThe defence argued diminished responsibility under the Criminal Law (Insanity) Act 2006 (irishtimes.com)
  • courtDr Brenda Wright said Silver was suffering a relapse of bipolar disorder that contributed significantly to his actions (irishtimes.com)
  • courtProf Harry Kennedy said Silver showed functioning mental capacity by carrying out purposeful actions with specific intent (irishtimes.com)
  • courtKennedy cited Silver's ability to take control of the gun, pull the trigger, stand back, and point and aim at the victim's trunk (irishtimes.com)
  • courtThe appeal was heard before Judges John Edwards, Patrick McCarthy and Isobel Kennedy (irishtimes.com)
  • courtThe Court of Appeal reserved judgment (irishtimes.com)
  • courtSilver appealed his conviction claiming the State's psychiatric evidence contradicted the legal test for insanity. (irishmirror.ie)
  • courtSilver's lawyers argued his responsibility was substantially diminished by his mental illness and he qualified for a manslaughter verdict under the Criminal Law (Insanity) Act 2006. (irishmirror.ie)
  • courtConsultant psychiatrist Dr Brenda Wright said Silver was suffering a relapse of bipolar disorder which contributed significantly to his actions. (irishmirror.ie)
  • courtProfessor Harry Kennedy, called by the prosecution, said Silver showed a functioning mental capacity by carrying out purposeful actions with specific intent. (irishmirror.ie)
  • courtKennedy cited Silver's ability to take control of the gun, pull the trigger, stand back, support the gun in both hands, and point and aim at the victim's trunk as evidence of functioning mental capacity. (irishmirror.ie)
  • courtDominic McGinn SC argued that Professor Kennedy's evidence contradicted the legal test for insanity under the Act. (irishmirror.ie)
  • courtMichael Delaney SC for the DPP said the trial judge's charge had been entirely appropriate. (irishmirror.ie)
  • courtMr Justice John Edwards, presiding with Mr Justice Patrick McCarthy and Ms Justice Isobel Kennedy, reserved judgment. (irishmirror.ie)
  • sentenceSilver was jailed for life with a minimum of 40 years in April 2023 (irishtimes.com)
  • sentenceIn April 2023, Ms Justice Tara Burns jailed Silver for life with a minimum time to be served of 40 years. (irishmirror.ie)

The reporting

newest first
  1. 20 Mar2026
    In courtirishmirror.ie, follow-up
    Garda killer Stephen Silver launches bid for freedom

    Reports on Silver's Court of Appeal hearing where his counsel argued the prosecution's psychiatric evidence contradicted the legal test for insanity under the Criminal Law (Insanity) Act 2006; the court reserved judgment.

    victim, Colm Horkan, male, irish (judged from name)Colm Horkanconvicted, Stephen Silver, 49, male, named, irish (judged from name)Stephen Silver
  2. 19 Mar2026
    In courtirishtimes.com, follow-up
    Man convicted of murdering Garda Colm Horkan appeals verdict

    Appeal hearing at the Court of Appeal on 19 March 2026; Judges Edwards, McCarthy and Kennedy reserved judgment.

    convicted, Stephen Silver, 49, male, named, irish (judged from name)Stephen Silvervictim, Colm Horkan, male, irish (judged from name)Colm Horkan