Ex-IRS Agent Convicted in Elaborate Double Murder Plot Involving Family Au Pair

A former Internal Revenue Service criminal investigator was convicted Monday on all counts for the 2023 murders of his wife and a man he lured to their suburban Virginia home, closing a case that prosecutors described as a coldly calculated plot to escape marriage and start a new life with the family’s au pair.

Brendan Banfield, 40, showed no visible reaction as a Fairfax County Circuit Court jury found him guilty of two counts of aggravated murder, use of a firearm in commission of a felony, and child endangerment. The panel of seven women and five men reached its verdict after roughly nine hours of deliberation, concluding a three-week trial that exposed a tangled web of infidelity, digital deception, and violence.

Prosecutors successfully argued that Banfield, leveraging his federal law enforcement training, masterminded a plan to kill his 37-year-old wife, Christina—a pediatric intensive care nurse—and frame Joseph Ryan, 38, for her murder. The scheme involved the couple’s 25-year-old Brazilian au pair, Juliana Peres Magalhães, with whom Banfield was having an affair.

Evidence presented at trial revealed that Banfield and Magalhães created fake profiles on a fetish website, impersonating Christina Banfield to lure Ryan to the family’s Herndon home under the pretense of a violent sexual encounter. On the night of the killings, Magalhães waited outside while Ryan arrived, armed with a knife as the online persona had requested.

According to Magalhães’s testimony, given as part of a plea agreement, she then called Banfield to falsely report an intruder. Banfield returned home and, using his service weapon, shot Ryan dead. He then allegedly stabbed his wife multiple times in the neck, attempting to stage the scene to suggest Ryan had killed her before being shot in self-defense.

“He was in love with Juliana,” lead prosecutor Jenna Sands told jurors in closing arguments. “He needed to get rid of his wife so they could be together, and he was willing to destroy two other lives to do it.”

The prosecution’s case relied on forensic evidence, including blood spatter analysis indicating Christina’s blood had been dripped onto Ryan’s hands post-mortem, and digital records tracing the fake online accounts to devices used by the defendants. The couple’s then-four-year-old daughter was found unharmed but alone in the basement during the violence upstairs, leading to the child endangerment charge.

Banfield testified in his own defense, admitting he shot Ryan but claiming it was a legitimate act of defense upon finding Ryan attacking his wife. His attorney argued Magalhães had fabricated the murder plot narrative to secure a favorable plea deal. She previously pleaded guilty to reduced charges and was sentenced to time served.

The case has sent ripples through the affluent Northern Virginia community, highlighting dark undercurrents in a seemingly ordinary suburban household. Banfield now faces mandatory life in prison without parole. His sentencing is scheduled for May 8.

David Chen, retired FBI behavioral analyst: “This case reads like a textbook example of instrumental violence. The perpetrator used his professional knowledge to stage a crime scene, betting that the initial narrative would hold. It’s a stark reminder that the most dangerous threats sometimes come from within the home.”

Megan Powell, neighbor and family friend: “Christina was the kindest person. To think this was happening while she was caring for the most vulnerable children in her hospital… it’s devastating. The betrayal is unimaginable.”

Robert Hayes, legal commentator: “The plea deal for the au pair is a bitter pill. She was an active participant who walked free after testifying, while two people are dead. The justice system sometimes makes distasteful bargains, but it shouldn’t feel this unjust.”

Dr. Anita Sharma, clinical psychologist: “The psychological manipulation here is profound. The grooming of the au pair, the digital catfishing of the victim—it shows a prolonged, predatory mindset. The child’s trauma, growing up with this truth, will be lifelong.”