On a Friday morning three years ago, a horrific scene unfolded in a Northern Virginia home: A pediatric ICU nurse, Christine Banfield, was mortally wounded in her bedroom. She’d been repeatedly stabbed. With her was 39-year-old Joseph Ryan. He’d been fatally shot.
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The nurse’s husband — IRS special agent Brendan Banfield — told authorities he killed Ryan, a stranger, after the man attacked his wife.
What prosecutors say actually happened inside the Banfields’ Fairfax County home was the result of something far more convoluted and sinister — a deadly catfishing scheme that was motivated by an affair and relied on a fetish website to lure an unsuspecting man to his death.
The plot, they said, was planned and executed by Brendan Banfield and his mistress, the family’s Brazilian au pair.
For more on the story, tune it to “Temptation” on “Dateline” at 9 ET/8 CT tonight.
Brendan Banfield has maintained his innocence and called the allegations “absolutely crazy.” After a three-week trial earlier this year, he was convicted of aggravated murder and is set to be sentenced to a mandatory term of life in prison term next month.
The au pair, Juliana Peres Magalhaes, cooperated with authorities and pleaded guilty to manslaughter. She was sentenced to 10 years in prison.
The murder
On the morning of Feb. 24, 2023, Brendan Banfield told a 911 operator that he’d come upon that terrifying scene inside his home in Herndon, a suburban community near Washington, D.C. Authorities found him in the primary bedroom kneeling over his wife, Christine Banfield, 37, with one of his hands on her neck, Fairfax County homicide detective Thomas Gadell told “Dateline.”
She’d been stabbed multiple times and was later pronounced dead.
On a dog bed in the corner, Gadell said, they found Ryan. In the basement was the couple’s 4-year-old daughter. She was unharmed.
In a statement to police, Peres Magalhaes walked authorities through what happened: The au pair was preparing to go to the National Zoo with the Banfields’ daughter when she saw an unfamiliar SUV pull into the family’s driveway. So she called Brendan Banfield, who was at a nearby McDonald’s getting breakfast.
“I don’t know who is that,” she described telling Brendan Banfield, body camera video shows. “Please come here. I’m scared.”
They put the girl in the basement with a tablet, Peres Magalhaes said, then went upstairs and heard what she described as “spanking.”
In the bedroom, she said, they saw Christine Banfield on the floor and a man with a knife above her. Brendan Banfield pleaded with the man to drop the blade, she said, but the man refused and started stabbing her.
“I think Brendan shot him,” Peres Magalhaes said.
She told police that she shot the man as well.
Brendan Banfield declined to provide a statement to police.
The plea deal
In the months after the killings, authorities came to doubt the au pair’s account. A prosecutor in the case, Eric Clingan, told “Dateline” that it didn’t make sense — Ryan had a knife and Brendan Banfield had a gun, yet Ryan refused to drop his weapon.
Nor had Peres Magalhaes provided a satisfactory explanation for a second 911 call made from her phone on the morning of Feb. 24, Clingan said. In that call, which was made 13 minutes before the one that summoned police to the family’s home, the person on the line said nothing and hung up after only a few seconds, he said. But a male voice could be heard moaning in the background.
“A person was in an injured state, and yet it still took 13 minutes” for the other call to be placed, the prosecutor said. “It made no sense.”
Peres Magalhaes had already confessed to shooting Ryan while he was in what Clingan described as a prone, unthreatening position; in October 2023, authorities arrested and charged her with his murder. Nearly a year later, after the completion of a blood pattern analysis that pointed to Brendan Banfield as the person who’d held the knife inside the bedroom, authorities arrested him, too.
He pleaded not guilty to charges of aggravated murder and was held without bail.
Peres Magalhaes had also pleaded not guilty to the murder charge. But in the weeks after Brendan Banfield’s arrest, she told authorities she wanted to cooperate, Clingan said, and in a four-hour statement, she detailed her affair with Brendan Banfield and his plan to kill his wife, whom he described as “lazy” and “not a good mother,” a video of her statement shows.
Peres Magalhaes confirmed what some of the investigators had come to believe about the killings: it was a catfishing scheme. In the statement, she said they’d created a fake user profile on a fetish-focused social network — FetLife.com — using Christine Banfield’s laptop and posing as “Annastasia9,” a person seeking to act out a violent sexual fantasy with a stranger in her home.
Brendan Banfield wanted to find someone who liked to “play violent” and could be blamed for Christine Banfield’s murder, Peres Magalhaes said.
Ryan was that person, she said.
Authorities had learned that Ryan met other women through FetLife, but they described Ryan as a person who respected boundaries and wasn’t violent, Patrick Brusch, a retired captain with the Fairfax County Police Department, told “Dateline.”
Ryan, Brusch said, “was baited and hunted.”
Ryan agreed to bring restraints, rope and a knife to the Banfields’ home. Brendan Banfield planned on stabbing his wife with that blade after he shot Ryan, Peres Magalhaes told authorities.
She agreed to plead guilty to the lesser crime of manslaughter and testify against Brendan Banfield. In exchange for her cooperation, prosecutors would recommend she be sentenced to time served.
The conviction
Brendan Banfield’s trial began in a Fairfax County courtroom in January, nearly three years after the killing of Christine Banfield and Ryan. Peres Magalhaes testified for the prosecution, telling the jury about her affair with Brendan Banfield, his plan to kill Christine Banfield and the horrific scene on the morning of Feb. 24.
Brendan Banfield’s attorney grilled Peres Magalhaes, questioning why she took so long to provide her account to authorities and pointing to an offer she received from a streaming outlet for an interview. In an email presented in court, she told her mother she’d been offered $10,000 but believed she could negotiate a fee of more than twice that.
“We do deserve something,” she wrote in the message.
“What is it you deserve something for?” asked the attorney, John Carroll.
“For everything we’ve been through,” she said on the stand.
Brendan Banfield also testified, acknowledging his affair with Peres Magalhaes but denying that he played a role in planning or executing his wife’s murder. When he opened the door to his bedroom and saw Christine Banfield on the floor and a man behind her with a knife, he said he was “extremely terrified.”
He shot Ryan after he saw him stab her, he said.
A witness for the prosecution was able to refute a key part of Brendan Banfield’s account of that morning, however. In his testimony, Banfield said that he was on his way to a work meeting with his supervisor when he stopped at McDonald’s and Peres Magalhaes called him about the unfamiliar SUV in the driveway.
But after that testimony, Brendan Banfield’s supervisor told authorities that no meeting had been scheduled, lead prosecutor Jenna Sands told “Dateline.” In court, the supervisor testified that he’d been in Baltimore on an undercover operation.
On Feb. 2, after nine hours of deliberation, a jury convicted Brendan Banfield of aggravated murder. Eleven days later, a judge sentenced Peres Magalhaes to the maximum penalty allowed for a manslaughter conviction — 10 years in prison.
“Your actions were deliberate, self-serving and demonstrated a profound disregard for human life,” Circuit Court Chief Judge Penney Azcarate said. “That is the most serious manslaughter scenario that this court has ever seen.”
