A man pleaded guilty on Friday to the murder of his sister-in-law six weeks after she had married his brother David.
John Evans, 56, appeared at Luton crown court, via a video link from Bedford jail
He pleaded guilty to the murder of 70 years old Mary Evans on November 18 last year.
She died from stab wounds received as she was sitting behind the wheel of her car in Trent Road, Luton.
Mary, known as May was on her way to collect her grandson from school when she was attacked.
Evans of Thames Court, Trent Road in Luton, was told his case was being adjourned and he will be sentenced next month.
Judge Michael Kay QC said he will receive a life sentence and the only question to be decided is the minimum term he will have to serve.