Son killed mum as she called 999 to report him for poisoning dad

A former master’s student killed his mother as she reported him to the police for trying to poison his father.

Thomas Fraser stabbed Miriam MacDonald, 52, in the neck while she was on a 999 call last June 1.

The 31-year-old had earlier spiked a can of juice that his dad, Ian MacDonald, 55, had been drinking.

Fraser also turned the knives on Mr MacDonald before fleeing the family home in Inverness after brave neighbours stepped in to try and help the couple.

Mrs MacDonald never recovered from the attack and passed away in hospital.

Fraser was later traced by police and made a string of “disturbing” remarks, including: “I am Lucifer”.

He had faced charges of murder and attempted murder as he appeared in the dock at the High Court in Glasgow.

But Fraser was acquitted after prosecutors accepted he was suffering from a mental disorder at the time.

Fraser – who is a twin – lived with his parents following his move back in March 2023, having been studying for a PhD in Electronic engineering at Heriot-Watt University in Edinburgh.

He had previously been awarded a Master’s degree in the subject.

The court heard there had been a decline in his mental health at university.

He was said to have become “reclusive” on returning to Inverness.

Days before the attacks, Mr McDonald had been making a coffee using his Nespresso hot drinks maker when he discovered a “white residue” on the edge of the water tank.

Prosecutor Graeme Jessop KC said: “He suspected Thomas Fraser had potentially put some sort of cleaning substance into the coffee machine.”

Fraser was confronted by his parents, but he denied being responsible.

On the day of the incident, Mr McDonald took a drink from a can of Pepsi he had opened before leaving it unattended on a coffee table.

After the family had dinner, the dad had more of the fizzy juice.

Mr Jessop added: “Upon drinking from it, the contents tasted flat and had a chemical taste.

“This caused Ian MacDonald to spit it out into the kitchen sink.”

Mrs MacDonald this time spoke to their son and quizzed him on what he had put in the Pepsi.

He again “denied having any involvement or knowledge” of it, but the mum still went on to dial 999 with concerns that Fraser had tried to poison his dad.

Mr Jessop then told the court: “While Miriam MacDonald was still on the phone, her husband started walking out of the kitchen.

“He looked behind him and saw Fraser holding a knife in each hand. He then proceeded to lunge towards Mr MacDonald.”

Fraser had grabbed one from a draining board that his dad had earlier used to peel potatoes, the other was described as a “black folding camping style-knife”.

The son initially slashed Mr MacDonald on the arm, then stabbed him in the chest.

Mrs MacDonald screamed down the phone: “Oh, they are fighting. Oh my God, he has got a knife. Can you please come? He’s coming with a knife.”

Mr MacDonald managed to stagger outside into the front garden.

Mr Jessop said: “While Miriam MacDonald was on the call to the handler, Fraser attacked her, striking her on the neck with a knife.”

Fraser then went back out to his stricken dad and hit him again.

Mrs MacDonald remained on the phone as she then also went out to the front garden.

Mr Jessop added: “She was still on the call to police when Fraser approached her and repeatedly stabbed her on the neck.”

Mr MacDonald desperately pushed his son away before slumping onto the road, where he was again struck by Fraser.

Two neighbours heard what was happening – they armed themselves with a shovel and a golf club to chase Fraser away.

The court heard how Mrs MacDonald’s condition deteriorated and she was rushed to hospital for surgery. She passed away the next evening.

Mr MacDonald suffered a number of wounds, including to his chest, arm and hands.

Fraser fled, but he was traced later that night at a riverbank, clutching a blood-stained knife.

Mr Jessop said he was arrested and went on to make a number of incriminating comments.

These included him confessing that he tried to kill both his parents and had also attempted to poison his dad.

On being charged with the attack on Mr MacDonald, he replied: “Embarrassing, I did not finish the job.”

In connection with the killing of his mum, Fraser said: “They were both dead years ago anyway.”

The court heard there was evidence of a “bleaching agent” and paracetamol around the mouth of the Pepsi can.

Fraser appeared in court having been brought from the State Hospital at Carstairs.

Psychiatrists concluded Fraser was suffering from a mental disorder at the time and did not appreciate the “nature or wrongfulness” of his conduct.

The hearing was told Fraser believed his parents had been killed and taken over by a “demonic entity”.

Donald Findlay KC, defending, said: “He is a very intelligent young man, an outstanding career in prospect in government service in relation to radar and all sorts of research matters.

“But, something terrible has gone wrong.”

Lord Mulholland adjourned the hearing until July for updated medical reports, and Fraser will remain in Carstairs for treatment.

It is likely he will eventually be made the subject of compulsion and restriction orders for him to stay there without limit of time.