Virginia au pair murder: Fetish plot, affair, gun range tied to double homicide at home, prosecutors say

An alleged affair and a fetish website connection were revealed this week in the case of a Virginia au pair who prosecutors say was involved in a double homicide at the home where she worked.

Prosecutors also said at a probable cause hearing on Monday that Juliana Peres Magalhaes and Brendan Banfield visited a gun range together before his wife, Christine Banfield, was killed during a double homicide at their home in February 2023.

Brendan and Peres Magalhaes have said Christine was killed by a stranger named Joseph Ryan, whom they shot after Ryan stabbed Christine.

It's part of a bizarre story that led to a murder case against Peres Magalhaes, which a judge ruled on Monday can proceed to a grand jury this month, NBC Washington reported.

VIRGINIA AU PAIR CHARGED IN MAN'S MURDER AT HOME OF DOUBLE HOMICIDE: POLICE

Brendan and Peres Magalhaes have said that Christine summoned Ryan to her Herndon home on a website for sexual bondage enthusiasts to connect, according to court documents. 

Brendan, who is an IRS criminal investigative division agent, told a 911 dispatcher that he shot Ryan with his service weapon after the fully clothed man stabbed the mother of his 4-year-old daughter, the Washington Post reported. 

While Ryan was on the ground, prosecutors claim, Brazilian national Peres Magalhaes retrieved another gun from elsewhere in the home and fired the shot that killed him. According to court documents, she told police that Brendan instructed her to do so. 

Prosecutors, who described Peres Magalhaes as Brendan's "girlfriend" and "live-in lover," said the au pair's lingerie and a framed photo of her and Brendan were found in the room where the stabbing and shooting took place, NBC 4 Washington reported.

But after a months-long investigation, the 23-year-old was arrested by the Fairfax County Police Department and charged with second-degree murder in Ryan's death. Brendan has not been charged with a crime, and no one has been charged in his wife's death.

However, Fairfax County Police Chief Kevin Davis told NBC Washington that he expects "that we will eventually be able to hold more than just one person accountable for this crime."

"I suspected from the very beginning – and I went to the scene of that double murder – that there was going to be a lot of twists and turns to this investigation," he told the outlet. "The twists and turns are still ongoing."

YOUNGKIN MOURNS K-9 DOG STABBED TO DEATH BY 'BARBARIC' MS-13 GANG MEMBERS: 'WILL BE HELD ACCOUNTABLE'

The Fairfax County Commonwealth Attorney's Office is exploring the possibility that someone posed as Christine on the fetish website to lure Ryan to the home for the purpose of killing the IRS agent's wife, WRC-TV reported. 

The account was set up on Christine's laptop – but messages on the fetish website between her and Ryan were inconsistent with her communication style, her loved ones reportedly told investigators. 

But at Monday's probable cause hearing for Peres Magalhaes, prosecutors focused on establishing the surviving Banfield's affair with the au pair accused of murder, WRC-TV reported. 

Previously, Fairfax County Commonwealth's Assistant Attorney Kelsey Gill said Peres Magalhaes and Brendan began their relationship several months before the two deaths occurred, and that they continued that relationship after Christine died. 

TEACHER'S CHILDREN FOUND WITH SLAIN MOM AFTER 'DISGUISED' HUSBAND KIDNAPPED THEM: POLICE

Brendan and Peres Magalhaes purchased the Glock used to shoot Ryan on a trip to a shooting range on Jan. 28 of last year, weeks before the incident, WTOP reported. 

In court, Commonwealth Assistant Attorney Eric Clingan said the gun was used to "eliminate the only existing witness," according to the station. 

Gill previously questioned why Brendan only shot Ryan after he stabbed his wife several times and has questioned whether Peres Magalhaes really shot the man at Brendan's behest, the Washington Post reported. 

Ryan Campbell, the nanny's lawyer, said in December that his client acted in self-defense, according to the newspaper: 

"He had just stabbed Christine Banfield," Campbell said. "It seems perfectly reasonable that a second shot would be fired to make sure that he’s not a threat to Brendan or Christine or Juliana."

Campbell could not immediately be reached for comment.

Brendan invoked his Fifth Amendment right when questioned on the stand at Monday's hearing, WTOP reported. To date, according to the outlet, he has yet to speak with authorities about the fatal events of Feb. 24 last year.

Brendan had no comment outside court on Monday, NBC Washington reported.