Brendan Banfield Fatally Stabbed His Wife with the Help of His Au Pair Lover. Inside His Life Today

Behind the picket fences of a quiet Virginia suburb, a family’s au pair was hiding more than just dirty laundry. New details now paint a chilling picture of betrayal that ended in two deaths—and left a little girl without her mother.

Here’s the full story as it unfolded in court.

Brendan Banfield, a former IRS criminal investigator, and his wife Christine seemed to live an ordinary life in Herndon. They had a 4-year-old daughter, Valerie, and Christine worked as a pediatric ICU nurse—a woman colleagues describe as an angel.

But according to court documents and testimony, something dark was brewing inside the home.

The family’s live-in au pair, Juliana Peres Magalhães, reportedly began an 𝒶𝒻𝒻𝒶𝒾𝓇 with Brendan around October 2022. During the trial, Peres Magalhães claimed Brendan told her divorce wasn’t an option because of money and custody concerns. Text messages and social media posts later showed the pair at a firing range and even in a bathtub together.

Prosecutors alleged that Brendan created a profile on a fetish website, pretending to be Christine. Through that account, he allegedly communicated with a man named Joseph Ryan about a violent sexual encounter.

On February 23, 2023, police were called to the Banfield home. Inside, they found Christine stabbed to death and Ryan shot in the head and chest. Valerie was discovered unharmed in the basement.

Initially, Brendan and Peres Magalhães claimed it was a home invasion gone wrong. But investigators soon uncovered evidence of the 𝒶𝒻𝒻𝒶𝒾𝓇, plus photos and travel records that reportedly showed the couple planning the crime.

Peres Magalhães later pleaded guilty to involuntary manslaughter and agreed to testify against Brendan. In February 2026, a jury found Brendan guilty of aggravated murder in the deaths of both Christine and Ryan. He was also convicted of child endangerment and using a firearm in a felony.

At his June 2026 sentencing, the judge told Brendan he had taken everything from his daughter. He was ordered to spend the rest of his life behind bars.

As for Peres Magalhães, she received a 10-year prison sentence. The judge told her she deserved incarceration and a life of reflection for her role in the tragedy.

Christine’s friends and family continue to honor her memory—not as a headline, but as a devoted nurse and mother.

What do you think justice looks like in a case where a child loses both parents to violence and prison?