In 1997 while acting as a Garda witness , Bowden named Holland in a Dublin court as the man he supplied the .357 Magnum gun to , and hence suspected of shooting Guerin . In the wake of Guerin 's killing , a period in which the Garda and the Criminal Assets Bureau made over 150 arrests to clear up Ireland 's illegal drug problem , Holland was arrested at Dún Laoghaire ferry port on 9 April 1997 . Initially arrested for involvement in Guerin 's murder , after an inspection of his premises and assets he was eventually charged for possession and distribution of of cannabis . During the trial in Dublin , Gardaí officer Marion Cusack said that she believed Holland was the gunman who killed Guerin in her car . Sentenced to 20 years for drug distribution , it was reduced to 12 years on appeal . The CAB subsequently seized a small house near Brittas , County Wicklow , in compensation . Whilst in Portlaoise Prison , he befriended Colm Murphy , the first person to be convicted in connection with the Omagh bombing , but was resisted by his fellow members of the Real IRA from entering their area of the jail
Omagh bombing
Omagh bombing
Patrick Holland (criminal)