A former loyalist paramilitary commander turned supergrass has pleaded guilty to 200 terrorist offences, including five murders.
Gary Haggarty, the ex-chief of the Ulster Volunteer Force's notorious north Belfast unit, admitted the litany of crimes as part of his deal with the State to give evidence against fellow terrorists.
As well as the five murders, the 45-year-old, who is currently in protective custody, admitted five attempted murders, including against police officers; 23 counts of conspiracy to murder; directing terrorism; and membership of a proscribed organisation, when he appeared before a judge at Belfast Crown Court.
Haggarty, who worked as a police informant during the Troubles, was interviewed more than 1,000 times by detectives in one of the biggest and most complex cases ever undertaken in Northern Ireland.
The catalogue of offences stretch over a 16-year period from 1991 to 2007 and include the loyalist murders of John Harbinson, Sean McParland, Gary Convie, Eamon Fox and Sean McDermott.
The lengthy charge sheet also includes aiding and abetting murder, kidnap, possession of firearms, ammunition and explosives as well as hijacking, false imprisonment, arson, intimidation and conspiracy to riot.
Haggarty is expected to receive a heavily reduced sentence in exchange for his cooperation with the authorities.
He could well walk free, given he has already served three years in custody - the equivalent of a six year sentence.
Sentence is expected to be passed later in the year.
In the interim prosecutors will decide how to proceed with the evidence he has provided.
It is understood Haggarty has made allegations against 14 fellow loyalists, for crimes including four murders.
He has also given evidence in relation to alleged criminality by two former Royal Ulster Constabulary Special Branch handlers who worked with him when he was an informer.
The content of his interviews amounts to 23,000 pages of transcribed evidence.
There was a significant police presence in and around the court for the high-profile arraignment hearing.
Haggarty, who is believed to be living at a secret location outside Northern Ireland, was escorted into court through a side door by two specialist police officers.
He was initially arrested in 2009 and charged with the murder of Mr Harbinson.
He then indicated his willingness to turn state's witness and subsequently signed an agreement to become an assisting offender under the terms of the Serious Organised Crime and Police Act (Socpa).
The terror boss, whose address was formally recorded on the indictment sheet as care of a Belfast police station, stood in the dock dressed in a grey suit during the hearing before judge Mr Justice Treacy.
He said 'guilty' as each charge was put to him, the majority in short form summary.
Relatives of some of his victims watched on from the public gallery of the court.