The disgraced South Carolina lawyer was convicted on two counts of murder for shooting his wife Maggie and son Paul in 2021.
Kayleigh McEnany tweeted a graph showing a rise in murders in 2020 and blamed Biden.
A Vacaville man will be charged with felony arson and two additional murder charges, authorities announced.
The incident took place at a care home in south-east London in the early hours of Monday morning.
The Dorset officer was cleared of murdering Parry, his lover, but admitted manslaughter.
Victoria Woodhall, 31, was stabbed to death by her husband.
Mel Mustafa has vowed to set up a domestic violence charity in the name of the mother-of-three, whose life fell apart after she lost her job and home.
The force's commander said he was "horrified and disgusted" by the allegations.
Devastated Family Pay Tribute To Sisters Stabbed To Death In London Park As Police Search For Attacker
Police have released new photos of Bibaa Henry and Nicole Smallman taken in the Wembley park on the night of the fatal stabbings.
A murder investigation was launched after the bodies of Nicole Smallman and Bibaa Henry were found in Fryent Country Park, Wembley, on Sunday.