Trial set for Virginia man accused of conspiring with au pair to kill his wife and another man

Juliana Peres Magalhães, right, has said she and Brendan Banfield carried out a plan to kill his wife and another man. (Fairfax County Police Department via CNN Newsource)

Nearly eight months after Brendan Banfield’s wife and a stranger were killed in the Banfields’ Virginia home in February 2023, police returned to the scene of the killings.

They entered the home and went to the bedroom where Christine Banfield was fatally stabbed. There, on the bedside table, investigators found a framed photo of Brendan smiling with another woman – the family’s au pair, according to court records.

Brendan Banfield now faces a double-murder trial, with jury selection scheduled Monday, as prosecutors allege he plotted with the au pair to kill his wife and another man. Prosecutors say that man had been lured to the home to frame him for Christine’s death – and to make his own killing appear to be an act of self-defence.

Banfield – a former IRS agent, according to CNN affiliate WUSA – has pleaded not guilty to aggravated murder and a firearm offense in the fatal stabbing of his wife and the fatal shooting of Joseph Ryan.

Prosecutors say Brendan Banfield and the family’s Brazilian au pair, Juliana Peres Magalhães, were having an extra-marital affair and carried out the plan together. The salacious plot features allegations of BDSM sexual role play, trips to the gun range and false 911 calls, all in an attempt to kill Banfield’s wife and frame Ryan, according to prosecutors.

Peres Magalhães was initially charged with murder and has since pleaded guilty to a lesser count of involuntary manslaughter for fatally shooting Ryan.

She has agreed to co-operate with prosecutors in exchange for a recommendation that she be sentenced to time served, according to the plea agreement. She is likely to be the star witness in Banfield’s murder trial.

The trial is expected to last about four weeks.

Banfield has been held without bond since his arrest, according to police. He faces up to life in prison on the murder charges.

Salacious allegations to face jury

The case began with calls to 911 from within the Banfields’ Herndon, Virginia, home on Feb. 24, 2023. In one call, Banfield told dispatchers he’d shot a man who stabbed his wife, according to police. There was no forced entry at the home.

In an upstairs bedroom, police found Christine Banfield, 37, with stab wounds and Ryan, 39, dead of gunshot wounds nearby. She was taken to a hospital and later pronounced dead, according to Fairfax County Police Chief Kevin Davis.

Peres Magalhães, 25, was arrested and charged with second-degree murder and a firearm offence in October 2023 and has been in custody since her arrest.

When police searched the home, they found a framed photo of Banfield and Peres Magalhães smiling together on his bedside table.

A year later, in October 2024, court records show Peres Magalhães pleaded guilty to involuntary manslaughter. At a plea hearing, prosecutors read aloud a statement laying out the key allegations in the case.

As they alleged, Peres Magalhães began working as an au pair for the couple in late 2021, and in August 2022 she and Brendan Banfield began an extra-marital relationship.

“In the fall of 2022, Brendan Banfield expressed to Peres Magalhães his desire to be rid of his wife and soon thereafter began planning to kill his wife as well as, ultimately, Joseph Ryan, the victim in this case,” prosecutors said.

Banfield set up an account on Fetlife.com, a sexual fetish site, began communicating with Ryan and lured him to the Banfield home, prosecutors said. Ryan “likely believed” he was meeting Christine Banfield for a consensual sexual encounter involving “violent sexual role play” with a knife, prosecutors said.

Banfield directed Peres Magalhães to talk with Ryan in a phone call to confirm details, according to prosecutors. She expressed hesitation with the plan at various points, prosecutors said, but “he insisted it was too late for her to back out.”

Banfield taught the au pair how to fire a gun at a local gun range in the fall and winter of 2022, prosecutors said.

As part of their plan, when Ryan came to the home, Peres Magalhães called Banfield to report that a strange man was at the house, and Banfield was waiting at a nearby McDonald’s so he could return to the home quickly, prosecutors said.

He and Peres Magalhães put his child in the basement and then went upstairs to the Banfields’ bedroom, with Brendan Banfield holding his service weapon and the au pair holding a firearm he had purchased a month earlier, according to prosecutors.

“The two entered the bedroom and Joseph Ryan was holding Christine Banfield down,” prosecutors said. “Brendan Banfield called out, ‘Police officer,’ and then shot Joseph Ryan in the head, and Ryan fell away from Christine Banfield.”

Peres Magalhães called 911 but ended the call at Banfield’s direction, prosecutors said.

Banfield stabbed his wife, according to prosecutors. Peres Magalhães saw Ryan still moving and shot him, prosecutors said.

The au pair then called 911 again and they reported the killings as if Ryan was an intruder who had stabbed Banfield’s wife, according to prosecutors.

‘There was a lot more to what met the eye’

Banfield was indicted on murder charges in September 2024. The indictment alleges he “willfully, deliberately, and with premeditation” killed his wife and Ryan.

“I knew, I suspected, I had a feeling that there was a lot more to what met the eye that morning,” Chief Davis said. “And certainly it has taken a road, 570 days later, where we are finally in a position to announce that two persons are being charged and held responsible and introduced to our criminal justice system for these two murders.”

Weeks later, Peres Magalhães pleaded guilty to the lesser charge for shooting and killing Ryan, according to prosecutors.

“Today’s agreement marks a significant step forward in this case, and it is an important development in our pursuit of justice for the victims and their families,” Fairfax County Commonwealth’s Attorney Steve Descano said of the au pair’s guilty plea.

In addition, Banfield was indicted on a count of felony child abuse and neglect and felony child cruelty related to the killings in December 2024. His daughter, who was four at the time, was present at the scene, according to prosecutors.