The third husband of 'black widow' Penelope Jackson took his own life after discovering her affair with the man she would later murder, it has been claimed.
Dad-of-four Alan Warrender was left broken after finding out about his wife's secret tryst with David Jackson, according to his family.
The RAF chief engineer, 43, had also turned to drinking and was struggling with debts at the time of his death in 1993.
Jackson, 66, was sentenced to life in prison last month after stabbing Mr Jackson, 78, multiple times, including while he tried to call for an ambulance at their home in Berrow, Somerset.
The couple had been rowing about a birthday meal prior to the murder in February.
She told her murder trial she had suffered years of abuse at the hands of her victim.
An unnamed family member of Mr Warrender's told the Daily Mail: "There's no question that the affair drove him to his death.
"After what she did to him and his family before she went on to murder her next husband, she should never be released from prison.
"She is a ruthless, greedy, angry woman. She is a danger to society."
Mr Warrender had met Jackson at RAF St Athan in the Vale of Glamorgan in south Wales soon after her second marriage to MoD employee Tony Rothwell came to an end in the late 1980s.
And Mr Warrender was still married to his first wife, Beverley.
The relative said Mr Warrender and Beverley were "soulmates", having been married since their early 20s.
They had two daughters and an adopted son.
Jackson was working as a budget manager at the base at the time she met Mr Warrender.
Beverley found out about their affair before she died from breast cancer aged 36, the relative explained.
Jackson and Mr Warrender quickly moved in together and were married by 1988, with daughter Isabelle born two years later.
The family member said Mr Warrender's children from his previous marriage were shipped off to boarding school.
The pair, however, fell into debt and while Mr Warrender was away on work in Saudi Arabia, Jackson met Colonel David Jackson.
Mr Warrender found out about their affair on returning from the Middle East, while also allegedly finding Jackson had had his two healthy dogs put to sleep.
An inquest ruled his death as suicide, caused by carbon monoxide poisoning while the "balance of his mind was disturbed".
Mr Jackson adopted Isabelle after marrying Jackson in 1996.
Isabelle told her mum's murder trial in October "my whole world fell away from my feet" after she learned of Mr Jackson's death.
"From the moment when the police knocked on our door and told us what had happened, I had not only lost my dad but I had lost my mum too. My life was changed forever," she added.
For emotional support, you can call the Samaritans 24-hour helpline on 116 123, email jo@samaritans.org, visit a Samaritans branch in person or go to the Samaritans website.
