Au pair who had affair with Brendan Banfield describes alleged scheme to kill his wife and another man

By Lauren del Valle, CNN

(CNN) — The au pair who was having an affair with Brendan Banfield when he allegedly killed his wife and another man in February 2023 told jurors Tuesday about the killings – and the elaborate scheme she said she helped execute.

Prosecutors have alleged that plot was hatched with the au pair, Juliana Peres Magalhães, who was initially charged with murder in the case in October 2023. She has since pleaded guilty to a lesser count of involuntary manslaughter for fatally shooting Joseph Ryan, one of the victims.

The au pair agreed to cooperate with prosecutors against Banfield in exchange for a recommendation that she be sentenced to time served, according to the plea agreement.

Peres Magalhães described Tuesday – the first day of testimony in the double-murder trial – how the killings of Christine Banfield and Ryan unfolded after months of preparation that she said involved luring Ryan to the scene so he could be framed for Christine’s death.

The Virginia family’s Brazilian au pair said she saw Banfield stab his wife repeatedly – and described how she shot Ryan with a gun Banfield taught her to use.

“When I first saw that happening, I ran to the other side of the bed, and I was just crouching down … and covering my ears and covering my eyes,” Peres Magalhães said. “And a few times I looked and I was able to see him stabbing her.”

Banfield has pleaded not guilty to charges of aggravated murder, as well as using a firearm during the commission of a felony. He faces up to life in prison if convicted on the murder charges.

Au pair describes alleged scheme

Peres Magalhães first started living with the Banfields in October 2021, and an extra-marital affair with Brendan Banfield began in August 2022, she said. Banfield hatched his plan to kill his wife not long after the affair began, Peres Magalhães testified.

According to the au pair, Banfield thought his wife was a terrible mother and wanted to be with her instead. Banfield didn’t want to pay for a divorce or share custody on his young daughter, Peres Magalhães said.

Using his wife’s laptop while she was home, Peres Magalhães and Banfield created a fake email address and an account on a fetish website, where Banfield planned to find a man they could eventually frame for his wife’s murder, the au pair testified.

They were seeking someone who would carry out a violent rape fantasy, and the jury saw messages from the fetish website where Peres Magalhães said she and Banfield vetted possible candidates to fill the specific role. They found a few men open to the idea but ruled out candidates when they asked to meet in person first or have the sexual encounter somewhere other than Banfield’s home, Peres Magalhães said.

Eventually, they found Ryan, with whom Banfield spent a month cultivating a relationship, Peres Magalhães said.

“He made Brendan feel confident enough that he would be the person to play the role that he needed a person to play, which means being aggressive and hold her down and come over to the house and bring stuff,” Peres Magalhães testified.

During opening statements earlier in the day, Banfield’s defense attorney said investigators initially concluded Christine Banfield had control over her devices and accused law enforcement of manipulating evidence to pin the blame on his client.

And Peres Magalhães was arrested in October 2023 to pit her against Banfield, defense attorney John Carroll told the jury.

“The whole reason she was arrested was to flip her against my client,” Carroll said.

In her opening statement Tuesday morning, prosecutor Jenna Sands told the jury Ryan had been lured to the Banfields’ home for what he thought was a consensual sexual encounter with Christine Banfield.

“Those two individuals had no reason to know each other but for the plotting and planning of Brendan Banfield,” Sands said.

Before the killings, Brendan Banfield, posing as his wife, gave Ryan strict instructions, prosecutors said during their opening statements.

“The door will be unlocked. Christine will be asleep in bed. Come straight upstairs. Cut off the clothing. Tie her. Rape her. Simple and fun,” Sands told jurors, summarizing the alleged instructions. “That was how it was posed. They would not meet in person beforehand. Joe’s phones would be left in a car. Joe was to bring a knife, zip ties, chains and, most importantly, he was not to stop even if she looked terrible, even if she was calling for help. He was to follow through, because that’s what she really wanted.”

In Telegram messages before the killings, Ryan sent a photo of chains and a knife he planned to bring to the sexual encounter. The messages and the photo were shown in court.

Jurors heard purported lies on a 911 call

Banfield took several steps to create a scene he knew would eventually be investigated, Peres Magalhães testified. She and Banfield got new phones and Apple ID accounts, he checked his neighborhood for surveillance cameras, changed his morning routine and had soundproof windows installed in the days before the murders, Peres Magalhães testified.

As Christine Banfield slept upstairs on February 24, 2023, Banfield unlocked the house door for Ryan and confirmed his arrival time on his wife’s phone before shutting it off and hiding it in a kitchen drawer, according to Peres Magalhães. Banfield also gave Peres Magalhaes his personal firearm that she kept in her pocket.

Banfield, who was an IRS investigator at the time, had a separate service firearm on him, she said.

The au pair then waited with Banfield’s daughter in her car near the home, and set the plan in motion when she saw Ryan arrive. Peres Magalhães first called Christine – who didn’t pick up – and then Brendan Banfield, ostensibly to tell him she saw a strange man park in the driveway and enter the home.

Banfield returned quickly to the house from a nearby McDonald’s where he was waiting, Peres Magalhães said. The two entered the house through the basement and left his daughter there before heading upstairs to where the killings unfolded.

When they entered the bedroom, Christine Banfield yelled, “Brendan, he has a knife,” the au pair said.

Ryan looked up at them “shocked” and that’s when Banfield shot him, Peres Magalhães said.

Calls to 911 led police to the Banfields’ Herndon, Virginia, home, where they found Christine Banfield, 37, with several fatal stab wounds, and Ryan, 39, dead of gunshot wounds nearby.

Tuesday morning jurors heard the 911 calls made from the Banfields’ home.

One 911 recording made at 7:47 a.m. was disconnected after a dispatcher answered the call. A dispatcher then called the number back and left a message when no one picked up.

Before her husband stabbed her, Christine yelled to Peres Magalhães, “Juliana, call 911,” the au pair testified. Peres Magalhães said she made the call but hung up before saying anything at Brendan Banfield’s direction.

Then she watched Banfield repeatedly stab his wife in the face and neck, Peres Magalhães testified. She tried to cover her ears so she wouldn’t have to hear it, she recalled.

Banfield then spent several minutes manipulating the crime scene to make it appear like Ryan was an intruder, prosecutors have alleged. According to Peres Magalhães, he took a handful of his wife’s blood and dripped it on Ryan’s body.

At 8:02 a.m. Peres Magalhães called 911 again and spoke to a dispatcher, stuttering but eventually telling them her “friend” had been stabbed.

“I need help …. my friend, she’s been stabbed with a knife and now she’s bleeding a lot. I don’t know what to do anymore,” Peres Magalhães could be heard saying, according to the recording of the call played in court.

After attempting to relay the home address to the dispatcher but stuttering and gasping for breath, Banfield took the phone from Peres Magalhães.

He gave his name and identified himself as a federal agent.
Banfield then said, stuttering at times on the recording, “There’s somebody here, I shot him. But he stabbed her. She’s bleeding. She’s got several marks on her neck. What do I do?”

When she spoke to investigators later that day, Peres Magalhães gave them an account of the morning’s events that had been concocted by the defendant, she said.

“What I told the detectives that day, it was the version Brendan had told me (to share) if I was ever to talk to a lawyer,” Peres Magalhães said.

Defense refutes ‘catfish’ theory

During opening statements, Banfield’s attorney said prosecutors are pinning their entire case on the testimony of Peres Magalhães, 25, who he alleged has been forced into a position to lie in exchange for a lenient sentence. Carroll also accused law enforcement of manipulating evidence to fit the theory that Banfield “catfished” Ryan and posed as his wife.

Initial digital forensics analysis conducted by investigators found that Christine Banfield had control over her devices before her death, Carroll said Tuesday morning, and detectives who didn’t support the catfishing theory were removed from the case.

“In the world of digital forensics, there’s a saying, digital forensics doesn’t lie, people lie. And there’s going to be plenty to see. You’re going to see manipulation within the police department,” Carroll said.

In the commonwealth’s opening statement, Sands told jurors they won’t have to rely on testimony from Peres Magalhães because convincing “blood evidence” will be enough to convict Banfield.

“While Juliana presents us with the narrative, that story that we wouldn’t necessarily know but for her details, it is the blood evidence that you can rely upon without a doubt,” Sands said.

“The blood cannot lie, and the blood puts Brendan Banfield, standing over Christine, stabbing her in the neck until she died.”

Banfield was also 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 4 at the time, was present at the scene, according to prosecutors.

This story has been updated with additional information.

The-CNN-Wire
™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.

CNN’s Eric Levenson contributed to this report.