Au pair faces up to 10 years in prison for downgraded charge in Herndon double homicide

HERNDON, Va. - A northern Virginia au pair charged in connection to a deadly love affair has accepted a plea deal under a lesser charge.

Juliana Peres Magalaes, 24, pleaded guilty to manslaughter Tuesday for shooting and killing 39-year-old Joseph Ryan on February 24, 2023 inside the home where she worked as an au pair. Prosecutors said the shooting was part of a larger plot conspired between Peres Magalhaes and her employer 39-year-old Brendan Banfield to kill Banfield’s wife Christine. The 37-year-old was allegedly stabbed to death by her husband, who is now facing murder charges for her and Ryan’s deaths.

Peres Magalhaes was initially facing second-degree murder and firearm charges for shooting and killing Ryan.

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"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 Tuesday.

"Much of the information that led to this agreement cannot be made public at this time due to the upcoming trial against the other defendant [Brendan Banfield] in this matter."

Prosecutors said in court Tuesday, a sexual relationship between Peres Magalhaes and Banfield began in August 2023. That fall, Banfield allegedly told Peres Magalhaes he wanted to get rid of his wife. Prosecutors said Tuesday, Banfield used to a sex fetish website and "settled on Joseph Ryan" to lure him to the Herndon home on the morning of February 24, 2023.

"Ryan likely thought he was going to the home for a violent sexual foreplay," a prosecutor said in court Tuesday.

On the morning of the killings, prosecutors said Peres Magalhaes took the couple’s daughter to the zoo. Newly file court documents state Peres Magalhaes told police, she returned home soon after realizing she forgot their lunches and spotted Ryan’s car in the driveway.

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"When she could not reach Chrstine, she contacted Brendan, who returned to the residence," the documents state.

In court Tuesday, prosecutors said Christine Banfield was unable to be reached because her phone was turned off and placed in a drawer downstairs by her husband. Once he and Peres Magalhaes returned to the home, prosecutors said they found Ryan in the Banfield’s bedroom with Christine, and Ryan was subsequently shot in the head and chest. Prosecutors believe Christine Banfield was stabbed in the neck by her husband and died at the hospital.

Kush Arora, a criminal defense attorney not affiliated with the case, said plea deals can be reached at any time during a court proceeding. Arora said it usually means the prosecution has an issue with their evidence, or a defendant is found to be not as culpable of a crime as initially thought.

"But what I suspect particularly based on the Commonwealth’s comments after the plea was entered, is there is some cooperation happening on her part in other co-defendant’s case later this year," Arora said, referring to this case.

Peres Magalhaes’ plea deal could be a "game changer" for Banfield’s case currently scheduled for a trial in February 2025, Arora added. While the Fairfax County Commonwealth’s Attorney’s Office could not confirm whether Peres Magalhaes will cooperate in Banfield’s trial, Arora said anything is possible.

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"Co-defendants who are cooperating obviously are going to strengthen the Commonwealth’s case, and that could change the decision of another party on whether they choose to go to trial or potentially choose to resolve their case," he said. "There is always a question when there is cooperation on the other side about what that person is getting in exchange for that cooperation. If someone is being given a lesser charge, if they are not given jail time in exchange for their testimony, defense attorneys are always going to use that in the courtroom to demonstrate the bias of the other party."

Peres Magalhaes faces up to 10 years for the manslaughter charge. A sentencing date has been set for March 21, 2025. Banfield’s trial is set for Feb. 3, 2025. He faces a life sentence for the aggravated murder charges.