The case, widely referred to as the “au pair affair,” centers on the February 2023 killings of Christine Banfield and Joseph Ryan at the couple’s northern Virginia home. Banfield has pleaded not guilty and could face life in prison if convicted. The prosecution’s key witness is Juliana Peres Magalhães, the family’s Brazilian au pair, who pleaded guilty to manslaughter in 2024 after cooperating with investigators.
Prosecutors told a Fairfax County, Virginia, jury Tuesday that Brendan Banfield used a fake online profile and a staged sexual scenario to lure a stranger to his home as part of a plan to kill his wife, while defense attorneys countered that the prosecution’s star witness invented her account after more than a year of maintaining her innocence.
Banfield is charged with aggravated murder in the Feb. 24, 2023, killings of Christine Banfield and Joseph Ryan at the couple’s home in northern Virginia. He has pleaded not guilty and could face life in prison if convicted. The trial’s central figure is Juliana Peres Magalhães, the family’s Brazilian au pair, who pleaded guilty to manslaughter in 2024 after cooperating with investigators and will be sentenced when the current trial concludes.
Prosecution’s account
Chief Deputy Commonwealth’s Attorney Jenna Sands told jurors that Banfield and Magalhães spent a month arranging a scenario in which Ryan would come to the home believing he had been invited to act out a sexual fantasy. Ryan was to arrive while Christine Banfield was sleeping, bringing restraints and a knife, Sands said.
Magalhães testified that she began working for the family in October 2021, at which point she would have been about 21 years old, and that she and Brendan Banfield began a sexual relationship about 10 months later. He told her he wanted to marry her and have children with her but needed to “get rid of” his wife, she said. Banfield did not want a divorce, Magalhães testified, because “she would have more money than he would” and because he wanted custody of the couple’s 4-year-old daughter.
The scheme, she said, involved creating a fake profile for Christine Banfield on a sexual fetish website, posting to it from Christine’s laptop and only when Christine was home. “He knew that we needed to have some alibis,” Magalhães said.
In preparation, both Banfield and Magalhães traded in their phones. Banfield also changed the windows to improve soundproofing and checked neighbors’ homes for doorbell cameras, Magalhães said.
The morning of the killings
On the morning of Feb. 24, 2023, Magalhães left the home with the couple’s daughter and waited in her car. Banfield drove to a nearby McDonald’s. When Magalhães called, he returned. The two brought the child to the basement, then went upstairs.
“When I got to the bedroom, he yelled, ‘Police officer,’” Magalhães said of Banfield. “Christine yelled back at Brendan, saying, ‘Brendan! He has a knife!’ That’s when Brendan first shot Joe.”
Christine Banfield told Magalhães to call 911. She did, then hung up after Banfield motioned to her, she said. Returning from the bathroom with towels, she found Banfield stabbing his wife. At some point she also shot Ryan — with a gun Banfield had given her that morning — after seeing him move, she testified. She called 911 a second time when Banfield gave her the signal, she said.
Defense challenges the witness
Defense attorney John Carroll told jurors that Magalhães had maintained her innocence for more than a year before changing her account. “The whole reason she was arrested was to flip her against my client,” Carroll said.
Carroll said both the lead homicide detective and the forensic detective disagreed with the prosecution’s theory that Banfield and Magalhães had been “catfishing” Ryan by impersonating Christine Banfield online. He said both were later transferred and described what he called “turmoil” within the police department over the case.
“You’re going to see a presentation of a horrible, tragic, awful event,” Carroll said. He acknowledged the affair was not in dispute but told jurors “there’s an awful lot more to look for.”
Banfield is also charged with child abuse and felony child cruelty in connection with the case; those counts will be decided alongside the aggravated murder charges.