Seamus Daly had faced 29 murder charges
Murder charges against the only remaining Omagh bombing suspect have been dropped by prosecutors.
Seamus Daly was charged with killing 29 people, including a pregnant woman carrying twins, in the 1998 car bomb attack by the Real IRA. Fifteen of the dead were under the age of 21.
He refused to make a comment as he was released from Maghaberry high-security prison in Co Antrim and greeted by his family.
The case against the 45-year-old, who had been in custody since April 2014, appeared to collapse last month when the prosecution's star witness contradicted himself during a pre-trial hearing.
"A number of issues" had been found when Denis O'Connor, a builder from Kilkenny, was cross-examined - with prosecutors concluding this "impacted upon the reliability of the evidence".
Michael Gallagher, whose son Aiden was among those killed in the explosion, has expressed outrage that victims' families were kept in the dark over the prosecution's collapse - and claimed they "have been failed once again" by the criminal justice system".
He added: "We just feel this was the last chance for justice for Omagh, and that is now over. It's very difficult to deal with, and we have to meet with our legal team to discuss the best way forward".
Outside court in Ballymena, he expressed hope that the victims' families will be able to meet with the North's justice minister to discuss the "serious issues" that have arisen during 18 years of failed attempts to secure a criminal conviction.
In 2009, Daly was among four men who were successfully sued in a civil case mounted by bereaved families, and a judge found he was liable for the attack.
At the time, they were ordered to pay stg£1.6m (€2.05m) in damages to victims and their relatives, but that money is yet to be recovered.
Reporter David Blevins said the criminal case had always been complicated for prosecutors - as they had been working with their colleagues here to obtain mobile phone records from the time.
Daly's lawyer, Peter Corrigan, has said the prosecution's case was built on a "house of straw" - and added his client is planning to take legal action over his two years' incarceration awaiting a trial.
The Omagh atrocity, which came four months after the Good Friday Agreement was signed, was the single deadliest atrocity of the Northern Ireland Troubles.
Spanish exchange students and three generations of the same family were also among those killed in the attack, which unfolded on a busy shopping street on a sunny afternoon in the height of summer. More than 300 others were also injured.