Christine Banfield, a pediatric intensive care nurse, lived in Herndon, Fairfax County, Virginia, with her husband, Brendan Banfield, a former Internal Revenue Service agent, and their young daughter. In 2022, the Banfields employed Juliana Peres Magalhães, a Brazilian national, as an au pair. During her employment, Brendan Banfield and Peres Magalhães began an extramarital affair, which included a trip together to New York City. Prosecutors said that during the relationship, Brendan Banfield expressed a desire to end his marriage without financial repercussions or a custody dispute involving his daughter.
Prosecutors said Brendan Banfield created a fake account on the fetish website FetLife under Christine Banfield's name and used it to lure Joseph Ryan, a Washington, D.C. resident with no known prior connection to the Banfield family, to the Banfields' home under the false pretense that Christine wanted to take part in a BDSM encounter.
On the morning of February 24, 2023, police responded to 911 calls from the Banfield residence in Herndon. Officers found Christine Banfield with multiple stab wounds and Joseph Ryan dead of gunshot wounds inside an upstairs bedroom. There were no signs of forced entry, and the Banfields' young daughter was found unharmed in the basement. Brendan Banfield and Peres Magalhães initially told police that Ryan had entered the house, attacked Christine with a knife, and was then shot by both of them in self-defense. Investigators concluded that this account was contradicted by physical and digital evidence, and prosecutors said the scene had been deliberately arranged to look like a home invasion.
Peres Magalhães was arrested in October 2023 and charged with second-degree murder and firearm offenses. Brendan Banfield was indicted on multiple counts in September 2024; he was taken into custody and denied bond as a flight risk and a danger to his young daughter. In October 2024, Peres Magalhães pleaded guilty to involuntary manslaughter in Ryan's death and agreed to testify against Brendan Banfield as part of a plea agreement.
A Fairfax County jury convicted Brendan Banfield of the aggravated murder of his wife and Joseph Ryan on February 2, 2026, after a trial in which prosecutors presented the case as a premeditated plot by Banfield and Peres Magalhães to kill Ryan and stage the scene as a home invasion gone wrong. The following week, a judge sentenced Peres Magalhães to ten years in prison, declining the prosecution's recommendation, made pursuant to her plea agreement, that she receive credit for time served. In June 2026, Brendan Banfield was sentenced to consecutive life sentences without the possibility of parole.
The case, referred to in media coverage as the "au pair affair" and the "au pair murders," drew extensive attention because of the extramarital affair between Brendan Banfield and Peres Magalhães, the alleged use of a fetish website to lure Ryan to the home, and the prosecution's account that the defendants staged the scene after the fact.