Double murderer Ian Stewart is to appeal against his whole-life sentence.
Earlier this year Stewart was convicted of the 2010 murder of his wife, six years before he went on to murder his fiancee.
He killed 51-year-old children's book author Helen Bailey in 2016, and dumped her body in the cesspit of the £1.5m home they shared in Royston in Hertfordshire.
A trial previously heard it was most likely she was suffocated while sedated by drugs, and Stewart was found guilty of her murder in 2017.
After this conviction, police investigated the 2010 death of Stewart's first wife, Diane Stewart, 47.
The cause of her death was recorded at the time as sudden unexplained death in epilepsy, but in February Stewart was found guilty of her murder.
Stewart told his trial at Huntingdon Crown Court that he found Ms Stewart collapsed in the garden of their home in Bassingbourn in Cambridgeshire when he returned from the supermarket.
He said he tried to revive her, attempted to contact neighbours who were a doctor and nurse, tried again to revive his wife, and then called 999.
Stewart is one of five killers who will have challenges or appeals to their whole life sentences heard in front of senior judges.
The hearing is expected to take place at the Royal Courts of Justice in central London from 4 May.