Brendan Banfield, Ex-IRS Officer, Guilty of Double Murder in Au Pair Affair

A Fairfax County jury convicted Brendan Banfield, 40, on two counts of aggravated murder, a firearms-related count and child endangerment, concluding prosecutors proved he plotted with the family’s Brazilian au pair to lure and kill two people at his Herndon home. The verdict, announced just after 5 p.m., leaves Banfield facing life in prison under Virginia law and a sentencing hearing set for May 8, 2026.

The killings took place on Feb. 24, 2023, at the Banfields’ large house on a cul-de-sac in suburban Herndon. Police found Christine Banfield, 37, stabbed in the upper body and later died of her injuries. Joseph Ryan, 39, was found shot to death. Investigators say the morning began with 911 calls placed by the au pair, Juliana Peres Magalhães, 25, and that Banfield told a dispatcher an “unknown male” had entered his home and attacked his wife.

Prosecutors told jurors the deaths were premeditated and the product of an elaborate scheme. They say Banfield and Magalhães impersonated Christine on a fetish website to lure Joseph Ryan to the house and planned to frame him as the attacker so Banfield could start a new life with the au pair. Magalhães pleaded guilty to manslaughter in 2024 and testified for the prosecution under a plea agreement that, prosecutors say, included time served in exchange for her cooperation. The case’s salacious details helped it draw national and international attention and spawned true-crime coverage online.

Banfield maintained his innocence at trial and took the stand in his own defense. He told jurors he came home to find Ryan attacking his wife with a knife and that he shot Ryan while trying to save Christine. He admitted to infidelity but denied conspiring to kill his wife, telling the court, “I think that it’s an absurd line of questioning for something that is not serious that a plan was made to get rid of my wife. That is absolutely crazy.” Defense attorney John Carroll challenged Magalhães’ credibility as a cooperating witness, arguing her testimony was motivated by a deal to avoid a longer sentence.

The 12-member jury, seven women and five men, deliberated across two days and logged nearly nine hours before returning guilty verdicts. Observers noted Banfield rose to hear the verdict and appeared stoic. Afterward, Fairfax County Commonwealth’s Attorney Steve Descano described Banfield’s actions and testimony outside the courthouse as “monstrous.” Jenna Sands, chief deputy commonwealth’s attorney, said of Banfield’s courtroom demeanor, “He was not truthful. He was cold. He showed absolutely no human emotion that we expected to see in someone in his position.”

For a community still processing the shock of a suburban double homicide tied to an au pair affair and online enticement, the case underscores questions about trust, digital lures and the role of plea bargaining in securing testimony. The immediate next step is sentencing on May 8, 2026, after which legal appeals and further fallout can be expected.