The case against William Stobie collapsed
Stobie was a former so-called quartermaster of the Loyalist paramilitary group the Ulster Defence Association.
The Belfast born paramilitary was also a self-confessed special branch informer.
The case against him has been running for more than 10 years.
During that time he has made several court appearances and has been the main witness of a major inquiry into RUC collusion.
But until recently few details were known of this controversial figure who was once a British soldier, and was later involved in the Ulster Defence Association and was a RUC informer.
The trial of Stobie over the killing of Catholic solicitor Pat Finucane in 1989 and Protestant teenager Adam Lambert in 1987 collapsed in November.
Lord Chief Justice Sir Robert Carswell returned a verdict of not guilty in the absence of evidence against him.
Questioned
Stobie's story began with his arrest in 1987.
While being questioned by the police, he claimed he was pressurised into working as an informer.
Two years later, Stobie claimed he tipped off his special branch handlers that a murder of a Catholic was imminent, but said nothing was done to prevent it or to apprehend those responsible.
It was about this time Pat Finucane was shot.
The Finucane case was central to allegations that the RUC colluded with loyalists in murdering Catholics.
Inquiry
In the 10 years preceding Stobie's arrest, the Finucane family continually asked for an independent inquiry into their father's murder.
A special investigation was later set up headed by the Deputy Commissioner of the Metropolitan Police, John Stevens.
The Finucane family are continuing to call for a public inquiry into their father's murder.
But the case against Stobie collapsed when the chief prosecution witness, Neil Mulholland, said he was unwilling to give evidence.
After the case Mr Stobie, speaking in the Irish News, said: "There have been four victims in this whole case - Pat Finucane, Adam Lambert, Neil Mulholland and myself.
"People may find that strange for me to say but it's true.
"It has been two years and five months and the establishment knew every day of it that I was innocent."