A former Royal Marine has been sentenced to 18 years in prison for amassing an arsenal of bomb materials intended for use in terror attacks by dissident Irish republicans.

Ciaran Maxwell, 31, had pleaded guilty to a string of terror offences. His sentence also included five years on extended licence.

Counter-terrorism sources say it is possible that the collection of weapons hidden by Maxwell in 43 caches in Northern Ireland and England may have been used to attack the UK – and some of it may still be in the hands of terrorists.

Maxwell’s arsenal included handguns, stolen military ammunition, homemade bombs and a digital dossier of more than 300 potential government and military targets; these included named individuals as well as buildings in both Britain and Northern Ireland.

Mr Justice Sweeney said he had considered imposing a life term, but that Maxwell had told police after his arrest of other arms dumps they had not known about and pleaded guilty, earning him a discount on his sentence.

Maxwell, dressed in a green T-shirt, showed no emotion during the sentencing remarks. He waived his right to appear in court, instead following proceedings via videolink from prison.

The judge said Maxwell carried out activities with Niall Lehd, from his home town of Larne, Northern Ireland, who was a member of the Continuity IRA: “The two of you worked together with Lehd in the senior role.”

Lehd has already been sentenced to six years in jail for his offences.

A hide used by Maxwell at Powderham New Plantation, near his home in Devon. Photograph: Metropolitan police

The judge rejected Maxwell’s claim that post-traumatic stress disorder suffered after a beating by loyalists in 2002 had driven his behaviour. Sweeney said: “I am sure that you were and will remain motivated by Dissident Republican sympathies and hostility to the United Kingdom, that you have considerable skills as a terrorist bomb maker, and that you enjoy the work involved.”

Sweeney said Maxwell was a “quartermaster” to the Continuity IRA and engaged in “sophisticated offending on a substantial scale” for five years until his arrest in 2016. “A skilled bombmaker is of considerable importance to a terrorist organisation like the Continuity IRA,” Sweeney said. “Your actions had the potential to threaten the political stability of Northern Ireland.”

The chance discovery by members of the public of two arms dumps in 2016 triggered a huge police and MI5 operation and round-the-clock surveillance of Maxwell.

So serious was the threat posed by the arsenal that it was a significant factor in the UK’s terror threat level being raised in 2016 to substantial. At least four dissident republican attacks in Northern Ireland are believed to have been carried out with weapons supplied by Maxwell.

The Old Bailey heard that Maxwell’s 43 hiding places were spread across eight locations. He used special forces manuals to help hide the equipment and even used an Islamist terrorist manual to further his support for violent republicanism and to derail the Irish peace agreement.

Richard Whittam, prosecuting, told the court: “Across 14 of the locations involved in the investigation, Mr Maxwell had in his possession, or had constructed, 14 pipe bombs. Of those 14 pipe bombs constructed by Mr Maxwell, four have been deployed in Northern Ireland.”

Paul Hynes QC, defending, said Maxwell lived a double life and was a “marine by day [and], it seems, Republican bombmaker on leave”.

Maxwell used bitcoins, the internet currency, to buy his weapons and chemicals online. Photograph: None

“Mr Maxwell accepts he was a bombmaker and quartermaster for bomb parts,” he said.

Maxwell, of Exminster, Devon, was a serving Royal Marine with 40 Commando based at Norton Manor Camp in Taunton, having enlisted in 2010.

Asked by the judge where Maxwell built the bombs, Hynes said: “Principally in Northern Ireland, mostly at his grandmother’s house. She died in 2015, but he was able to use her address before that, very occasionally, for a few bits and bobs.”

Maxwell used bitcoin, the internet currency, to buy his weapons online. The password for his wifi connection was “tiocfaidh1” – a reference to the Irish republican phrase Tiocfaidh ár lá, meaning “our day will come”.

Maxwell’s haul included an adapted Police Service of Northern Ireland (PSNI) pass card, a PSNI uniform and a police stab-proof vest – all hidden at locations in across Northern Ireland and the south-west of England.

The Ministry of Defence is under scrutiny over how Maxwell was able to join the elite Royal Navy squad of marines in 2010, receiving high-level combat and weapons training.

Hynes denied the arsenal was meant to be used to attack the UK. But prosecutors said Maxwell’s actions posed a threat to national security: “We say this was activity that did threaten the democratic government and the security of the state.”

A police stab vest was found among the cache of weapons and chemicals. Photograph: Metropolitan Police

Police strongly believe that Maxwell’s weapons were used in at least four dissident republican attacks in Northern Ireland, three of which took place in the last year, although no one was injured in the attacks.

Asst Ch Con Stephen Martin of PSNI said: “We assess there’s a strong likelihood that items associated with Maxwell have made their way into the hands of violent dissident republican groups in Northern Ireland and four of these items have been used – three in the last year. Not all of those devices detonated. Some did.”

Investigations into Maxwell’s links to dissident republicanism are continuing and at least one arrest has been made.

In March 2016 a member of the public found two barrels hidden in the ground of Carnfunnock Country Park in Northern Ireland. Inside were chemicals and materials needed to make explosives.

Maxwell pleaded guilty to engaging in conduct in preparation of terrorist acts, as well as possession with intent to supply cannabis and possession of articles for use in fraud. Photograph: Pool/Reuters

In May 2016, in Capanagh Forest, a member of the public found similar items. Three blue barrels were buried in the ground containing a handgun, ammo, two anti-personnel mines and various pipe bombs in different stages of manufacture.

In August 2016 a DNA test identified Maxwell, whose profile had been recorded when he was questioned as a suspect in a previous assault case.

A handwritten note by Maxwell, discovered in an underground hide in Powderham New Plantation in Devon. Photograph: HO/AFP/Getty Images

PSNI officers, with help from English colleagues, began trailing Maxwell, which led to the discovery of 19 separate caches of chemicals, memory cards and lists of potential targets. They also found booby-trapped torches, 100kg of explosives, and a makeshift cannabis factory. In total 2,413 exhibits were found.

After the verdict police released photographs that showed Maxwell in his cannabis factory, pipe bombs, timers, a balaclava and handwritten notes detailing his plans including to “make more caches” - “long term”, “operational”, and “functional”.





Maxwell pleaded guilty in February to assisting another to commit acts of terrorism between 2011 and 2016, as well as charges relating to possession of cannabis and fraud.

After the case, Martin called Maxwell “an extremely dangerous individual”. He said of the sentence: “There is no doubt in my mind that Northern Ireland and England are safer places to live.”