The family of a murdered Aberdeen grandmother have said they still have “unanswered questions” after it was revealed her killer had committed more than 70 crimes before her death.
Norman Duncan was jailed for life after a “horrendous” and “sustained” knife attack on 54-year-old Margaret Robertson on September 25 2019.
Margaret’s near-naked body was discovered in her bloodstained bedroom at her Seaton flat in Promenade Court after she was sexually assaulted and stabbed to death.
His trial revealed the 43-year-old killer had 74 previous convictions and more than three-quarters of those offences earned him jail time in the past.
Jurors were told Duncan’s record included convictions for serious assault, assault with a weapon, assault with intent to rob and mobbing and rioting.
Margaret’s children, Michelle and Mark said: “Our mum didn’t deserve to die that day and especially in the horrendous, brutal way it happened.
“We still have unanswered questions as to why it happened at all.
“This man has taken so much from us and impacted on our lives in many ways.”
A history of violence
The dad-of-two has been abusing drugs since he was in his mid-20s and has spent much of his life behind bars.
In 2010, aged 32, a jury at the High Court in Edinburgh convicted him of a vicious bottle attack that left his victim scarred for life.
Even back then, Duncan’s history of violence was noted by the courts, with advocate depute Peter McCormack telling judge Kenneth Maciver that he had nine pages of previous convictions, including serious assault.
The judge said: “Regrettably your record not only is appalling in almost every respect, but it is particularly bad in respect of serious assaults.”
Later, after stealing more than £2000 of cash and goods including money from people’s pay packets, Duncan was jailed for three years in November 2013.
Less than a year before Margaret’s murder Duncan was serving a sentence at HMP Grampian in Peterhead but his behaviour was of such concern he was moved into psychiatric care.
On October 14 2018, while he was receiving psychiatric treatment at Perth’s Murray Royal Hospital, he cracked a metal plate in a nurse’s mouth and ended up in the dock again.
Perth Sheriff Court was told the unprovoked attack came about after the nurse refused to give Duncan a cup of coffee in the early hours of the morning.
For that assault he was jailed for seven months.
Abusing drugs in prison
During the murder trial, defence solicitor advocate Iain Paterson said Duncan was diagnosed with a schizo affective disorder and was taking antipsychotic medication.
But proceedings were halted when it emerged that the accused had been abusing psychoactive drugs while in prison.
At the time, Duncan was deemed medically unfit for trial and the hearing was put on hold while the 43-year-old was treated at the high-security State Hospital at Carstairs.
Duncan was later returned to the prison system and proceedings picked up again.
Senior Investigating Officer, Detective Inspector Gary Winter said: “Margaret suffered a horrendous and sustained attack in her own flat – a place where she should have been safe.
“This was a particularly challenging investigation and the successful outcome at court was only achieved as a result of the professionalism and collaborative working of a number of agencies involved.”
He added: “In particular I would like to thank local officers and officers from across Police Scotland’s Major Investigation Teams, Scene Examiners and Forensic staff from across the Scottish Police Authority, as well as staff at the Crown Office and Procurator Fiscal Service.”
The Det Insp also thanked members of the local community who he said provided “vital information” in connection with the investigation at the time.
“As a result of the support we received from the public, as well as extensive forensic and CCTV work, we have now ensured that this extremely violent individual will be held to account for his actions that day,” he added.
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