New details emerge in murder case involving mistress au pair of Virginia family and fetish-seeking man

New revelations came to light this week in a Virginia murder case where a family’s au pair – who was having an affair with the husband – was charged with fatally shooting another man moments after he allegedly stabbed the cheating spouse’s wife, according to officials and reports.

The mysterious case began more than a year ago when Christine Banfield, 37 was fatally stabbed by Joseph Ryan, who arrived at the Herndon, VA house after he was solicited from a sexual fetish website.

Ryan, 39, was then shot by both Banfield’s husband Brendan and his apparent mistress Juliana Peres Magalhaes, authorities have said.

Brendan Banfield, who is an IRS criminal investigative division agent, and Peres Magalhaes saw Ryan, who was fully clothed, hold a knife to a naked Christine Banfield, prosecutors said, according to the Washington Post.  

Brendan told a 911 dispatcher he shot at Ryan with his service weapon when Ryan started stabbing Christine Banfield, and Peres Magalhaes, 23, told authorities she then shot Ryan while he was on the ground after she retrieved another gun from a different room at the direction of Brendan Banfield, prosecutors reportedly said.

Magalhaes gunshot proved to be the fatal one, officials have said.

Only the au pair was arrested last October and charged with the murder of Ryan, and no one has been charged in the death of Banfield, though prosecutors have hinted there might be more going on beyond the gruesome Feb. 24, 2023 scene.

Fairfax County Commonwealth’s Assistant Attorney Kelsey Gill previously said Peres Magalhaes and Brendan began an affair several months leading out to the deadly shooting, per the Washington Post.

And on Monday, it was revealed during a preliminary hearing that the pair, which continued their relationship following the deaths, went to a shooting range weeks before Christine Banfield and Ryan were killed.

Prosecutors provided business records to back up the claim and said Brendan Banfield bought a Glock from the range on Jan. 28, 2023, WTOP reported.

The Glock was used by Peres Magalhaes when she shot Ryan, prosecutors alleged.

Commonwealth Assistant Attorney Eric Clingan said in court the gun was used to “eliminate the only living witness,” according to the station.

Ryan arrived at the house after he was asked to come over through a website that caters to sexual fetishes, Gill said last December, according to the Washington Post.

The account was set up on Christine Banfield’s laptop, but prosecutors have not confirmed who was behind the online profile.

Christine Banfield bought tickets for Magalhaes to take Banfields’ young daughter to the zoo around the time Ryan came over, Magalhaes’ defense lawyer has said.

Magalhaes told authorities she spotted Ryan going into the house and called Brendan Banfield to return home, which is when they discovered Ryan and Banfield in the bedroom, the Washington Post reported.

Gill, the Commonwealth attorney, previously questioned why Brendan Banfield would only shoot at Ryan after he stabbed his wife several times, and if Brendan really directed Magalhaes to grab the other gun, according to the newspaper.

The au pair’s lawyer, Ryan Campbell, has claimed his client acted in self-defense.

“He had just stabbed Christine Banfield,” Campbell reportedly said in December. “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.”

During Monday’s hearing, Brendan Banfield reportedly pleaded the fifth when questioned on the stand.