Prior to the death of journalist Veronica Guerin, the State had no adequate apparatus to combat organised crime.
In the year before her death, 12 people were shot dead in crime-related killings in Dublin alone. The Garda knew who the murderers were but could not bring prosecutions.
It had also been known for up to two years that Gilligan's gang had introduced a new degree of ruthless violence to the crime world. A number of the murders were ascribed to his gang.
Gilligan was flaunting his wealth from drug trafficking. His wife, Geraldine, moved from a corporation house in Ballyfermot and was living in a £1,000,000-plus equestrian centre at Mucklon, Co Kildare. Jessbrook was on the verge of being one of the top equestrian centres in the State.
British and Dutch criminals were living equally ostentatious lifestyles here, confident that the State was not prepared to take any action beyond the strict constitutional interpretation of the criminal law.
Well-organised Irish criminals and foreign criminals based in Ireland enjoyed virtual immunity from prosecution. That changed on the afternoon of June 26th when Gilligan's gang murdered Ms Guerin.
Ms Guerin had made a career out of tracing and exposing the State's wealthiest criminals. It was a mark of the criminals' self-confidence and the perceived inadequacy of the criminal justice system that they were prepared to believe they could murder her and suffer no serious long-term consequences.
For a while after the murder, it appeared the State was not prepared to make anything other than a token response. However, a public exasperated by the flood of drugs into the State and by the sight of rich criminals laughing at the law was not prepared to accept the death of the popular journalist.
As public anger mounted and wreaths of flowers began filling the railings outside Leinster House, the Fine Gael/Labour coalition was moved to action.
Criminal assets seizure legislation, based on a model drawn up by Mr Eamon Leahy SC, one of the leading prosecuting barristers in the Gilligan case, and the present Minister for Justice, Mr O'Donoghue, was brought into law by the autumn of 1996.
The British Home Office and police forces are now emulating this legislation and the Garda Criminal Assets Bureau (CAB). Other EU states are examining the Act and the work of CAB.
The automatic right to bail in all cases was withdrawn by referendum. The new bail law was enacted at the end of 1999.
For the first time the State used "accomplice witnesses": three key members of Gilligan's gang who were prepared to accept jail sentences for their roles and give evidence against the principals in the murder.
Other police forces, particularly those in Italy, who have faced massive criminal conspiracies from the Mafia and Camorra, have found that the use of such witnesses - known as penittii or penitents - was essential in countering organised criminals. The FBI and US police forces had also developed the use of such witnesses against the Mafia.
The Guerin case also led, for the first time, to the establishment of a State witness protection scheme, again similar to those used by the FBI and Italian police where the witnesses and their families received 24hour protection.
The State decided to hold the Gilligan trial in the juryless Special Criminal Court. Both organised criminals and terrorists in this State have records of intimidating juries.
The Garda also used, for the first time, detailed evidence taken from Eircom records of the mobile telephone calls made by the gang. This provided strong circumstantial evidence which backed the evidence given by the State's witnesses.
Gilligan's conviction was secured despite a 44-day adversarial battle between lawyers costing millions of pounds paid for by public funds. By contrast, Gilligan's associate, John Cunningham, the Dutch-based Irish drug trafficker, received only a two-day public hearing before being sentence to nine years' imprisonment in January.
Gilligan, with millions of pounds at his disposal, deployed an array of stratagems from legal challenges, delaying tactics and even public relations exercises in an effort to destroy the case against him. In response, the Garda Commissioner, Mr Pat Byrne, appointed his best and toughest investigators and gave them whatever resources they needed. Up to 70 officers were engaged in the investigation at various times, although only a permanent core of 12 remained on the case throughout.
The Guerin case showed the State was capable of an effective response to organised crime. Drugs still reach the Republic in large amounts but there are no organised criminal gangs left in this State on anything like the scale of Gilligan's gang.