The predatory partner of Helen Bailey is facing the rest of his life in jail for drugging and killing the children's author in a plot to inherit her vast fortune.
Ian Stewart, 56, is likely to "end his days behind bars" after he smothered the Electra Brown writer and dragged her body into a foul sewage pit below their home.
She was found, alongside her dog Boris, in the cesspit hidden deep below their garage three months after she abruptly disappeared in April last year.
Stewart was convicted of the "despicable" killing in a unanimous verdict at St Albans Crown Court, prompting police to turn their focus on the sudden death of his first wife.
The former software engineer then refused to return to the dock as his sentencing proceedings began on Wednesday afternoon.
Simon Russell Flint, defending, said during his mitigation: "It has to be acknowledged that, as the jury's verdict reflects, he has burdened both the family of Helen Bailey and his own family with incalculable loss, a lifetime of misery, sorrow and suffering and he will have a long time to reflect on the consequences of those actions.
"The likelihood is, given his state of health, the sentence has a like-effect of a whole-life order.
"There is every prospect and likelihood Mr Stewart will end his days behind bars."
Stewart targeted the vulnerable widow on the internet in 2011, earning his way into her trust and later her £3.3 million estate after launching a "love-bombing" offensive.
He became the chief heir to her riches, standing to gain around £1.8 million from her investment portfolio, plus the value of their home in Royston, Hertfordshire, and her coastal cottage in Kent.
Over many weeks, Stewart surreptitiously fed Ms Bailey his prescription anti-insomnia drug, Zopiclone, possibly by slipping it into her morning scrambled eggs.
Hours after the murder, he illicitly boosted a standing order to himself from her account, earning him an extra £12,000 over the three months following her disappearance.
Judge Andrew Bright, who will sentence Stewart at 10am on Thursday, told Mr Russell Flint: "You will have a hard job to persuade me this wasn't a murder for gain, it's quite clear to me that it was."
He added: "He may have had mixed motives, one doesn't know what other motives there could have been, quite frankly. But money is, in my judgment, the most obvious and principal reason he did what he did."
Detectives are to probe the sudden death of Stewart's first wife, who was found in the couple's garden in 2010.
An inquest at the time concluded she died of natural causes from a "sudden unexpected death in epilepsy".
Her body was cremated, police said.
Detective Chief Inspector Jerome Kent said: "There is not a murder investigation into Diane Stewart, there is a re-examination of a sudden, unexpected death. It is only right that I would look back on somebody's past."