A POLITICALLY-obsessed pensioner discussed the "assassination" of Nicola Sturgeon before helping assault a sheriff during a violent "citizen's arrest".

William Curtis directed the threatening online remarks towards the First Minister which were discovered by her private office in Edinburgh in 2019.

The 71-year-old ex-fishing skipper also continued a sinister hate campaign against his then local MSP Stewart Stevenson that year.

He sent a YouTube video link relating to the murder of Labour MP Jo Cox with the message: "Your time is coming, for that you can be sure".

Curtis and 60-year-old Philip Mitchell then teamed up to target Sheriff Robert McDonald on June 29, 2021.

READ MORE: Man found seriously hurt in flat as cops make arrest

Mitchell wrestled the 67-year-old to the ground near to Banff Sheriff Court in Aberdeenshire before sitting on top of him.

Curtis stood nearby filming on his phone while encouraging his accomplice.

The pair - both held on remand - had denied the charges during a protracted trial.

There were repeated accusations the court, prosecutors and the Scottish Government were "corrupt".

Jurors heard further bizarre claims the sheriff attack footage had been tampered with before being played to the jury.

Curtis meantime insisted his then partner was responsible for targeting then SNP politician Mr Stevenson.

Curtis was today found guilty of three charges of threatening and abusive behaviour towards the First Minister, Mr Stevenson as well as to a former neighbour and local housing officer.

The crimes spanned between February 2019 and October 2020 at Curtis's home in Aberchirder, Aberdeenshire.

He and Mitchell were also convicted of the assault and abduction of Sheriff McDonald.

Lord Weir deferred sentencing on both at the High Court in Glasgow for reports.

The trial heard of an initial "threatening" email which Ms Sturgeon's office intercepted in February 27, 2019, sent from a "Billy Curtis".

Among other detail, the message included claims of "mitigating offences" apparently committed by the First Minister.

It went on: "We do not intend to harm her, but if her security attempt to stop the rights of a citizen's arrest on an ongoing crime...

"Well, as the police are so good at saying, reasonable force will be used."

The trial then heard of a Facebook posting which had been passed on from Stewart Stevenson's office.

This was in the name of William Patrick Curtis.

Jurors were again read what was stated once more mentioning a 'citizen's arrest" of Ms Sturgeon for "treason".

But, it added: "Over the last three years serious people, who feel the abuse to the electorate by her criminal activities warrants assassination of her and several of her ministers.

"On down to even civilians who work in all these agencies who have repeatedly lied to the electorate and conspired with the First Minister."

It was signed off "The Skipper xxxx".

In March 2019, Curtis continued to hassle Mr Stevenson.

He had been fined the previous year for threatening the then Banffshire and Buchan Coast MSP.

A Facebook message read: "Your time is coming, for that you can be sure."

There was also a YouTube video relating to then recent death of Labour MP Jo Cox.

There was another message which read: "I fully intend to haunt you. You corrupt b*****d".

In June 2021, Curtis and Mitchell were caught on camera confronting Sheriff McDonald at a car park next to the court where he presided.

Mitchell shouted: "You are Sheriff Robert McDonald and I am here to make a citizen's arrest."

Sheriff McDonald had previously ruled in his favour in a dispute Mitchell had been having with the DVLA.

The lawyer: "I tried to break free, but Mr Mitchell wrestled me to the ground and then sat on top of me.

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"I was flat on my back and Mr Mitchell was astride me. He was literally sitting across my waist."

"I was taken aback...in the civil case I had found in Mr Mitchell's favour as I had granted an appeal.

"It made no sense to me. I was annoyed, but totally bemused at what was going on."

Despite Mitchell urging police to arrest the sheriff, it was him and Curtis who ended up being held.

Curtis refuted all accusations even pinning the blame on then-partner Alyson Gould for targeting Mr Stevenson.

But, Miss Gould, 65, said Curtis had an "issue" with the former MSP and that he sounded off "24/7, seven days a week" about his "political views".

In evidence, Curtis claimed he was merely there as a "witness" that morning in the sheriff incident despite him being heard stating: "That's it - hold him down".

Curtis told prosecutor Chris McKenna: "Philip Mitchell is the one making the citizen's arrest. I was there to check on the man's wellbeing."

Both him and Mitchell claimed the footage played to jurors had been "doctored" to make them appear guilty.

Former HGV driver Mitchell said he was "compelled" to carry out the "citizen's arrest".

He defended himself for the majority of the trial.

During evidence at one stage, he had tried unsuccessfully - via his brother - to hire the services of leading KC Donald Findlay.

The trial was eventually held in Mitchell's absence due to his regular outbursts in the courtroom.

He was not in the dock for the verdict. It emerged he has previously been jailed for contempt of court.

The pair will be sentenced on March 3 in Edinburgh.