Detectives have identified high-ranking members of a killer dissident gang responsible for a terror campaign throughout Northern Ireland.
Police are monitoring a number of men active in terror cells across the province and across the border, and provided a rare insight into the huge scale of the operation being carried out by the security forces to contain them.
Police are investigating a number of off-shoots of the dissident gang, comprising around 20-25 individuals in total, based in Omagh, Coalisland, Toomebridge and Ballyronan on the northern shore of Lough Neagh, and Monaghan in the Irish Republic.
And they said the would-be killers are being directed by an overall leadership based in Belfast.
Officers have carried out 11,750 tasks or actions so far – that is already more than the 10,500 undertaken during the investigation into the Real IRA's 1998 Omagh bomb.
Investigators have linked the murder of young Catholic police officer Ronan Kerr to 16 other crimes committed by the inter-connected dissident republican umbrella group.
The 25-year-old was killed by a booby-trap car bomb explosion at his Omagh home in April 2011.
Police hunting for those behind the atrocity say they believe they have identified the man who made the bomb.
They say the dissident is based in the Republic of Ireland, describing him as "experienced and competent" at manufacturing murderous devices.
The year before Mr Kerr's murder, another officer, GAA enthusiast Peadar Heffron, suffered horrific injuries in a similar attack.
In relation to the 17 offences under investigation, detectives said they had gathered a significant amount of evidence linking three men to some of the most serious.
Among the incidents by the self-styled new IRA – directed by its Belfast leadership –were two failed murder bids that seriously injured two police officers, including Mr Heffron, and a car bomb attack on the Policing Board in Belfast.
In a further layer of complexity, police think some of the dissidents use a criminal gang in Omagh to secure some of their hardware.
Fourteen arrests have been made so far.
Police said the investigation could last for up to five years.
No charges have yet been brought against the men police yesterday earmarked as key dissident suspects, in either Mr Kerr's murder or the other offences, explaining that more time was needed to build the cases against them.
A senior police officer in charge of the police strategy to combat dissident republican terrorists yesterday welcomed the sentencing of an Omagh man for terror offences as a significant milestone.
The arsenal was described as the biggest weapons haul recovered in a decade.
Items found inside a lock-up garage included four AK47 assault rifles, Semtex, timer power units used for detonating bombs, ammunition, incendiary devices, a booster pack for an RPG7 rocket, and parts of an improvised PRIG grenade.
"The Mountjoy Road arms find is one of the biggest in recent years," said Assistant Chief Constable Drew Harris (below).
"On one very important level, it has saved lives and significantly disrupted a terrorist group.
"On another, more strategic, level, it forms part of the police investigation into a series of linked incidents which include Constable Kerr's murder.
"Although we have yet to bring charges for Ronan's murder, this investigation, which is the largest in the PSNI's history, is far from over.
"We have made progress and we believe there is potential to bring other individuals before the courts."
Details of the device used to kill Mr Kerr were revealed yesterday.
Police said magnets used in the device came from the sign of a taxi stolen in Omagh just over a fortnight before the murder.
"We will continue to pursue a comprehensive forensic strategy," added Mr Harris.
Jailed: man who kept weapons and explosives haul in a lock-up garage
A dissident republican who admitted possessing a large cache of guns and explosives has been sentenced to 10 years.
Gavin Coyle (36), from Omagh, Co Tyrone, was arrested in 2011 when detectives investigating the murder of newly-qualified policeman Ronan Kerr discovered the arms dump in a lock-up garage in the Tyrone town of Coalisland.
Items seized included Semtex plastic explosive, four AK47 assault rifles, ammunition and magazines, a booster for an RPG rocket; three bomb timer units, a number of electronic incendiary devices, components of an improvised PRIG grenade, explosive powder and detonating cord.
Last year Coyle, from Culmore Park, pleaded guilty to possession of explosives and firearms with intent to endanger life and membership of a proscribed organisation, namely the group that styles itself as the "new IRA".
Passing sentence at Belfast Crown Court, Judge Corinne Philpott said half of the 10-year term would be spent behind bars and the remainder on licence.
Coyle, dressed in a grey polo shirt and jeans, showed no emotion in the dock as the sentence was handed down.
Constable Kerr (25) was killed in April 2011 when a booby-trap bomb exploded under his car outside his home in Omagh. No one has been convicted in connection with the attack – claimed by members of the new IRA.
Detectives investigating their colleague's death have widened the probe to include 16 other crimes blamed on gangs belonging to the dissident group, with the discovery of the Coalisland arms dump considered a significant element of the inquiry.
It was uncovered within days of the police officer's murder.
Coyle was forensically linked to the weapons store by footprint analysis.
Coyle was given a six-year sentence for IRA membership, 10 years for possession of explosives and 10 for possession of firearms, with Judge Philpott ordering that the terms be served concurrently.
After hearing pleas from defence and prosecution lawyers, the judge said she had taken into account Coyle's admission of guilt in mitigation.
She said she had also factored in that the charges related to "keeping or assisting in keeping" the weapons for others, and not for deployment by himself.
But she said an aggravating factor was the nature of the weapons haul that had been found.
"It's very fortunate that police discovered these items before they could be put to use. Regarding the firearms, the AK47s are of some considerable vintage. It looks like these weapons have been re-activated," she said.
Coyle has already served around two years and eight months in custody.
After his licence expires, he will still have to notify police of his whereabouts for a further 10 years.