A Herndon man faces life in prison after being convicted today (Monday) of murdering his wife and another man while having an affair with the family’s au pair.
After a trial that spanned more than two weeks, it took just one-and-a-half days for the 12-person jury to return a verdict against Brendan Banfield, finding the 40-year-old former IRS officer guilty for the February 2023 murders of Christine Banfield and Joseph Ryan.
At 5:03 p.m. Monday, the jury’s foreperson announced a unanimous verdict that convicted Banfield on two counts of aggravated murder, one count of using a firearm in the commission of a felony, and one count of child endangerment.
Banfield had no physical reaction as the verdict was read in court.
“My hope with this is that he realizes he didn’t get away with it,” Fairfax County Commonwealth’s Attorney Steve Descano said. “Most of all, though, I hope he thinks about his wife and Joe, and about what a heinous thing he did, because that’s something that he is rightfully going to have to live with for the rest of his life.”
Prosecutors have long contended that Banfield orchestrated the killings in order to, essentially, start a new life with the family’s au pair, with whom he had been engaging in a months-long affair.
The au pair, Juliana Peres Magalhaes, was initially charged with one count of second-degree murder, though she later entered a guilty plea to the lesser charge of manslaughter on the condition that she aid prosecutors with their case against Banfield.
“If you have somebody in the room and they want to proffer, you’re not going to turn that down,” Descano said. “She told us some things that we had not known. We did check on her story [and] we felt confident in that story, confident enough to offer her the plea deal that we gave her and put her on the stand as part of our case.”
Banfield is scheduled to be sentenced on May 8. He faces a mandatory life sentence due to his conviction on aggravated murder charges.
“Our job is to follow the evidence,” Descano said. “We heard what Juliana said, we heard what Brendan said — those are our clues into what happened. But at the end of the day, we presented the evidence to the jury, and we’re just very, very pleased that we’re able to stand here knowing that we got justice for Joe and Christine.”
Peres Magalhaes is currently scheduled to be sentenced on Feb. 13. As a Brazilian citizen, she is expected to be deported back to the country at the conclusion of any sentence she receives.
The murders and investigation
Police responded to the Banfields’ home, located in the 13200 block of Stable Brook Way in the Floris area south of Herndon, early in the morning on Feb. 24, 2023.
Brendan Banfield and Peres Magalhaes had called 911 to report that Christine Banfield had been stabbed by an intruder. Brendan Banfield then claimed to have shot Joseph Ryan in an act of self-defense.
Ryan, who sustained two gunshot wounds, was pronounced dead inside the residence. Christine Banfield was transported to a local hospital, where she died.
With the Fairfax County Circuit Court closed due to weather, the Brendan #Banfield trial is on pause today.
Footage of Banfield being told that his wife, Christine, had died, was released in court last week. He is charged with the killings of her and another man. #AuPairTrial pic.twitter.com/4gl9lZ3ulF
— Jared Serre (@JaredSerre) January 26, 2026
Brendan Banfield and Peres Magalhaes, who later both testified to being involved in an extramarital affair with each other, were later accused of orchestrating the encounter through a “catfishing” scheme to help end the Banfields’ marriage, according to prosecutors.
Through evidence, prosecutors argued that the pair — while purporting to be Christine Banfield — lured Ryan to the home under the guise of a knife-related consensual sexual encounter. They created an account impersonating Christine Banfield on the sexual fetish website FetLife, prosecutors said.
Believing that he was meeting Christine Banfield, who had a day off from her job as a pediatric ICU nurse, Ryan instead found himself in the middle of an attempt to frame him for her murder.
According to prosecutors, Brendan Banfield and Peres Magalhaes both left the Banfield home around 7 a.m. Brendan was ostensibly going to work, while Peres Magalhaes claimed she was going to take the Banfields’ 4-year-old daughter to the zoo.
However, Peres Magalhaes actually stayed parked outside the home and notified Brendan Banfield when Ryan arrived. Waiting at a nearby McDonald’s, Brendan Banfield then joined Peres Magalhaes at the house, where they confronted Ryan and Christine Banfield.
Ryan was ultimately shot twice — first by Brendan Banfield and then by the au pair — and Christine Banfield was stabbed seven times in the neck by her husband, who used a knife that Ryan had brought to the home, prosecutors said.
Brendan Banfield was not initially considered a suspect, and was not arrested until his indictment in September 2024. Peres Magalhaes had previously been arrested and charged with one count of second-degree murder in October 2023.
During the trial, defense attorney John Carroll challenged the catfishing scenario detailed by prosecutors, arguing that Peres Magalhaes was testifying against Brendan Banfield to avoid a long prison sentence. He also called witnesses who suggested that the Fairfax County Police Department took investigators who disagreed with the prosecution’s theory off the case.
An officer who concluded from digital evidence that Christine Banfield was behind the social media account was later transferred in what Carroll said was punishment for disagreeing with a theory favored by the department’s higher-ups.
But prosecutor Jenna Sands pushed back on the notion that Banfield was unfamiliar with social media platforms for people interested in fetishes and couldn’t be capable of such catfishing.
“You had multiple affairs, correct?” Sands asked the defendant, followed by, “And one of those affairs was with a woman named Danielle, who you met on a fetish site searching for ‘sugar babies.’ Is that correct?”
Banfield replied: “I would not call it a fetish site.” When pressed as to how he would describe the website, Banfield testified that he had an arranged relationship with someone who knew he was married.
In closing arguments, Sands told the jury they did not have to rely solely on Magalhães’ testimony, pointing to what she called a “plethora of evidence.” That included expert testimony that blood stains on Ryan’s hands suggested Christine Banfield’s blood had been dripped onto him from above.
