Police Scotland have urged people to help tackle the radicalisation of friends and family members after an “unprecedented” case saw a man convicted under the Terrorism Act.

Gabrielle Friel, 22, was found guilty on Tuesday of possessing weapons at various locations in Edinburgh last summer, giving rise to the reasonable suspicion that possessing them was for a purpose connected with terrorism.

A second charge that he prepared for terrorist acts by researching spree killings, particularly those connected with incels – people who are involuntarily celibate – was found not proven, following a five-day trial at the High Court in Edinburgh.

As part of this charge, Friel was accused of having “expressed affinity with and sympathy for one incel-motivated mass murderer” and to have expressed “a desire to carry out a spree killing mass murder”.

After the verdict was reached at the High Court in Edinburgh, Police Scotland issued a statement which thanked health and social work partners for helping to intervene before potentially “catastrophic” consequences.

Assistant Chief Constable for counter-terrorism Pat Campbell said: “Gabrielle Friel is a potentially dangerous and disaffected individual, and Police Scotland welcomes the outcome of this case as the consequences of his actions could have been catastrophic.

“I sincerely thank the health and social care professionals and the Police Scotland officers involved in what was an extremely complex and challenging investigation.

“Their actions contributed to an early intervention and undoubtedly prevented him undertaking an act that threatened the safety of our communities.

“This was an unprecedented case and underlines the severity of Friel’s intentions.”

The court was told Friel amassed weapons last summer as he wanted to commit “suicide by cop” to help end his violent thoughts.

He said mass shooting was a “fantasy” for him and he “felt for” incel mass murderer Elliot Rodger, but denied being an incel and described killers as “evil”.

I know it can be a big step, particularly when we are referring to terrorism

The 2014 Isla Vista killer Rodger – who murdered six people and injured 14 others – has been described as a trigger moment for the misogynistic subculture, which often involves ideas of violence towards women due to a lack of sexual activity.

Friel had told a doctor he wanted to “carry out a mass shooting” and his social worker reported that he appeared to “almost idolise” Rodger.

Mr Campbell added: “We can’t do this alone and we also need the help of families, friends and the wider public.

“I know it can be a big step, particularly when we are referring to terrorism. But if you think that a family member or a friend is being radicalised, displaying extremist views or becoming involved in terrorist activity you should contact Police Scotland.

“Officers will work alongside other public protection partners to safeguard that individual and the public.

“By working together effectively, we will also help to safeguard individuals who have been identified as being vulnerable to radicalisation or being drawn into extremism.”