There were concerns last night in Government and Garda circles over the future of the State's witness protection programme after the Special Criminal Court acquitted John Gilligan of the murder of journalist Veronica Guerin.
Gilligan (51), once the State's most powerful criminal gang leader, was convicted on five counts of drug trafficking and sentenced to an unprecedented 28 years.
However, on the murder charge, the court rejected the evidence of Gilligan's former accomplice, Russell Warren, now in the witness protection scheme.
Warren had told the court he followed the journalist in his car to the Naas Road-Boot Road junction and watched as she was shot dead by the pillion passenger of a motorcycle. The court found Warren's evidence was insufficient to convict Gilligan of the murder offence.
Two other gang members, Brian Meehan and Paul Ward, are serving life terms for the murder of Ms Guerin. Their convictions were based partly on evidence from the same witnesses who gave evidence in Gilligan's trial.
The three witnesses in the State protection scheme, Warren, John Dunne and Charles Bowden, are all approaching the end of jail terms imposed for offences connected with the gang's drug-trafficking.
The Taoiseach last night pointedly paid tribute to the work of the Garda in the Gilligan case, but said he did not want to comment on the verdict.
Mr Ahern said: "I would like to pay tribute to the gardai for their outstanding and dedicated work on this case over a long period. My thoughts this evening are with the Guerin family."
After the sentencing yesterday, Garda Commissioner Mr Pat Byrne said the investigation into the remaining members of the gang which killed Ms Guerin would continue.
He was not disappointed by the failure to secure a murder conviction.
"We are very satisfied with the result today. It is not a question of how an individual is pleased or not pleased at the result. We operate in a professional manner. It is not a personal vendetta, nor should it have been. We operate this democracy within the law. Everyone is innocent until proven guilty and we operate within those bounds and regulations."
He said the Garda team involved had interviewed 1,400 people; taken 3,500 statements; carried out 425 searches; made 214 arrests; seized 105 firearms and large quantities of drugs. The Criminal Assets Bureau had also seized large sums of money made by the gang.
Assistant Garda Commissioner Mr Tony Hickey, who led the Garda team, defended the use of the three accomplice witnesses and the State's witness protection scheme.
He said the Garda would study the judgment and learn from it. However "the use of co-operative accomplices is one of the most important and effective means of fighting organised crime gangs".
Speaking outside the court, Gilligan's solicitor, Mr Joe Rice, said: "The fight goes on to establish his innocence . . . he is disappointed by the severity of the sentence. There will be an appeal against the conviction and, of course, an appeal against the sentence."
Mr Jimmy Guerin, brother of the murdered journalist, said: "I was disappointed that he was acquitted on the charge of murder but I am pleased with the sentence he was given in respect of the drugs."