A Swansea man has been jailed for having a stash of bomb-making manuals and instructions on how to carry out “lone wolf” knife attacks.
Lee Griffiths, 26, from Clydach, was caught with terrorist material, including copies of so-called Islamic State magazine Rumiyah and the Anarchist Cookbook.
He was jailed for five years and four months at the Old Bailey in London.
The court was told that Griffiths, a Muslim convert, had been radicalised.
He received a hospital order in 2011 for a knife attack on his mother while she slept, the court heard.
Following his discharge last August, and while living at a residential home for mental health service users, it was told Griffiths was quickly radicalised.
Extremist material was uncovered after police raided his bedroom and seized his mobile phone last January.
The judge, Mr Justice Saunders, said it was impossible to say whether Griffiths’ radicalisation was “as a result of the interventions of others or simply from what he found on the internet”.
Sentencing, he said: “I am not of course sentencing this defendant for preparation of terrorist acts himself at the time of his arrest.
“It cannot, however, in my judgment be ruled out that at some stage, because of his mental instability, the defendant could have made use of the information himself or have supplied it to another to enable them to carry out a terrorist outrage.
“Whatever the nature of the defendant’s mental problem, I accept that he is vulnerable but he is also dangerous.
“He has shown that he can be extremely violent for no reason and his radicalisation and beliefs cause considerable concern.”
Earlier, prosecutor Simon Davis said the defendant had been sent to a medium secure mental health unit in Bridgend after he attacked his mother.
He was released from the Carswell clinic in August 2016 on condition that he live at the residential home in Swansea where he was routinely searched by staff when he went out.
Mr Davis said staff had noticed he changed from being interested in fishing, cooking and football to becoming fixated with Islam and serial killers.
His views became more extreme by last October when he also attended a mosque in Swansea.
The defendant, who worked at a local food bank, was described as vulnerable and easily led but computer-literate.
Barrister Ian Ibrahim, for Griffiths, said it was difficult to mitigate in the wake of recent atrocities but stressed the defendant was a “young man with a history of psychiatric illness”.
Griffiths admitted five counts of possessing information which may be useful to someone who commits or prepares acts of terrorism and one of dissemination of a terrorist publication.