Au Pair Testifies She Helped Plot Alleged Scheme With Brendan Banfield to Kill His Wife and Frame a Stranger

The au pair, Juliana Peres Magalhães, testified Tuesday that she and Brendan Banfield conspired to lure Joseph Ryan to the Banfield home so he could be framed for the killing of Christine Banfield. Peres Magalhães described detailed preparations, the moments of the attack on Feb. 24, 2023, and her subsequent cooperation with prosecutors.

Allegations and Testimony

Prosecutors say Banfield and Peres Magalhães created a fake online persona and used a fetish website to recruit a man willing to participate in a staged violent encounter. According to Peres Magalhães, they vetted candidates until they identified Joseph Ryan, whom Banfield cultivated for roughly a month.

"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 testified. "And a few times I looked and I was able to see him stabbing her."

Peres Magalhães said Banfield stabbed his wife repeatedly while she crouched nearby. She also testified that she fatally shot Ryan with a gun Banfield taught her to use; she has pleaded guilty to involuntary manslaughter in Ryan’s death and is cooperating with prosecutors in exchange for a recommendation of time served.

Juliana Peres Magalhães, right, has said she and Brendan Banfield carried out a plan to kill his wife and another man. - Fairfax County Police Department

How Prosecutors Say the Plan Unfolded

According to the au pair’s testimony and prosecutors’ opening statements, Banfield posed as his wife in messages to Ryan and provided specific instructions: enter the home, go upstairs to where Christine was sleeping, cut off clothing, tie her and carry out a violent sexual assault. Telegram messages and a photo of chains and a knife that Ryan sent in advance were presented in court.

Prosecutors say Banfield took steps to stage the scene: obtaining new phones and Apple ID accounts, checking for neighborhood surveillance cameras, changing his routines, and installing soundproof windows shortly before the killings. On the morning of Feb. 24, Peres Magalhães said, Banfield unlocked the house for Ryan, shut off Christine’s phone and hid it, and gave Peres Magalhães his personal firearm.

Peres Magalhães said she waited in a car with the Banfields’ young daughter while Banfield and Ryan entered the home, then accompanied Banfield upstairs. She described hearing Christine cry out, "Brendan, he has a knife," seeing Ryan appear "shocked," and then watching Banfield shoot Ryan. Responding officers later found Christine with multiple stab wounds and Ryan dead of gunshot wounds.

Prosecutors say Christine Banfield, seen in this undated photo, was killed by her husband after he shot a man allegedly lured to the couple's Herndon, Virginia, home. - From Banfield family/WUSA

911 Calls, Crime-Scene Allegations and Evidence

Courtroom recordings of 911 calls from the morning were played for jurors. Peres Magalhães testified she made an initial 911 call at Banfield’s direction but hung up; a later call captured her telling a dispatcher that a friend had been stabbed. Prosecutors allege Banfield then manipulated the scene to make Ryan look like an intruder, including dripping Christine’s blood onto Ryan’s body.

Prosecutors emphasized blood evidence they say places Banfield at Christine’s bedside as she was stabbed. They presented messages from the fetish site and Telegram evidence showing weapons discussed in advance.

Defense Arguments

Banfield has pleaded not guilty to aggravated murder and related firearm charges. His attorney, John Carroll, told jurors investigators initially found Christine had control over her devices and accused law enforcement of manipulating evidence to fit a "catfishing" theory that Banfield posed as his wife. Carroll also asserted that Peres Magalhães was arrested and pressured to turn against Banfield.

This image, provided by the Fairfax County Police Department and taken on October 13, 2023, shows a framed photo of Brendan Banfield and Juliana Peres Magalhães on his bedside table in Herndon, Virginia. - Fairfax County Police Department/AP/File

Prosecutors counter that the physical and forensic evidence — especially the blood evidence — corroborates Peres Magalhães’s account.

Additional Charges and Context

Banfield, formerly an IRS investigator, also faces December 2024 indictments for felony child abuse and cruelty related to the killings; prosecutors say the couple’s 4-year-old daughter was present at the scene. If convicted of the murder charges, Banfield faces up to life in prison.

The trial continues as jurors weigh competing accounts: Peres Magalhães’s detailed testimony and the physical evidence presented by prosecutors versus the defense’s claims of evidence manipulation and coerced cooperation.