Guerin's murder caused outrage, and
Taoiseach John Bruton called it "an attack on democracy". After the murder of Guerin,
Charles Bowden was arrested as were the other members of Gilligan's gang who were still in Ireland. In an agreement with the
Attorney General of Ireland, Bowden agreed to turn state's witness, and become the first person to enter the Republic's
Witness Security Programme. Granted immunity from prosecution for the murder of Guerin, he was the only witness to give evidence against all four drug gang members at their trials in the
Special Criminal Court: Patrick Holland, Paul "Hippo" Ward, Brian Meehan and John Gilligan. The investigation into Guerin's death resulted in over 150 other arrests and convictions, as well as seizures of drugs and arms. In 1997, while acting as a Garda witness, Bowden named
Patrick "Dutchy" Holland in court as the man he supplied the gun to, and hence suspected of shooting Guerin. Holland was never convicted of the murder, and he denied the accusation until his death in June 2009 while in prison in the UK. In November 1998, after evidence from Bowden and others, Paul "Hippo" Ward was convicted of the murder and sentenced to
life in prison as an accomplice, because he had disposed of the murder weapon and the motorbike. This conviction was later overturned on appeal. Brian Meehan fled to
Amsterdam with Traynor (who later escaped to Portugal). After the court dismissed additional evidence from Bowden, Meehan was convicted on the testimony of gang member turned state's witness Russell Warren, who had followed Guerin's movements in the hours before the murder, and then called Meehan on a mobile phone with the details. Meehan was convicted of murdering Guerin, and sentenced to life imprisonment. He is the only individual serving a life sentence for his role in the murder. John Gilligan left Ireland the day before Guerin was murdered, on a flight to Amsterdam. He was arrested 12 months later in the United Kingdom trying to board a flight for Amsterdam after a routine search of his baggage revealed $500,000 in cash. Claiming it was the proceeds of gambling, he was charged with
money laundering. After a three-year legal battle, he was extradited to Ireland on 3 February 2000. Tried and
acquitted of Guerin's murder, Traynor, as of 2013, was living in
Kent, England after serving time in an English prison. Traynor died in 2021 of cancer. Turley remarried in 2011. Guerin and Turley's son, Cathal Turley, relocated to
Dubai and, as of 2021, manages an
Irish pub at the
Dubai World Trade Centre. ==Memorials and legacy==