Alex Murdaugh, the South Carolina lawyer convicted of murdering his wife and son, filed an appeal against his conviction, alleging jury tampering during his trial.
His attorneys say a county clerk pressured jurors to reach “a quick verdict” and told the panel “not to be fooled” by Murdaugh’s testimony.
They say the clerk “betrayed her oath of office for money and fame”.
Murdaugh, 55, was found guilty in March and sentenced to life without parole.
Murdaugh attorneys Jim Griffin and Dick Harpootlian told a news conference on Tuesday they want a new trial.
First, they are seeking an evidentiary hearing that they hope will grant them the ability to demand phone records and emails and speak to witnesses.
The lawyers spoke as they filed a motion with the South Carolina Court of Appeals, alleging that the Colleton County clerk of court, Rebecca Hill, had encouraged jurors not to be “misled” by Murdaugh.
The court papers – containing sworn statements from three of the jurors – allege that Ms Hill asked members of the panel for their opinions about Murdaugh’s guilt or innocence.
The filing also says she “invented a story about a Facebook post to remove a juror she believed might not vote guilty”.
The jury deliberated for less than three hours before convicting Murdaugh of shooting his wife, Maggie, and youngest son, Paul, at close range on their family estate in June 2021.
“Ms Hill did these things to secure for herself a book deal and media appearances that would not happen in the event of a mistrial,” the defence team said.
In July, Ms Hill published Behind the Doors of Justice: The Murdaugh Murders, a behind-the-scenes book from the trial.
The BBC has reached out to Ms Hill for comment.
Murdaugh, who was once an influential personal injury attorney in South Carolina, also faces charges of financial fraud related to his family’s law firm and the death of his former housekeeper.