A Virginia man having an affair with the family’s Brazilian au pair was found guilty Monday of murdering his wife and another man that prosecutors say was lured to the house as a fall guy.

Brendan Banfield, a former IRS law enforcement officer, told police he came across Joseph Ryan attacking his wife, Christine Banfield, with a knife on the morning of 24 February 2023. He shot Ryan and then Juliana Magalhães, the au pair, shot him, too.

But officials argued in court that the story was too good to be true, telling jurors that Banfield set Ryan up in a scheme to get rid of his wife. It later came out that Brendan Banfield and Magalhães had been having an affair.

Magalhães pleaded guilty to manslaughter in 2024 and testified against her former lover at trial. She said they had impersonated Christine Banfield, a pediatric intensive care nurse, on a website for sexual fetishes. She said they used the site to lure Ryan to the house for a sexual encounter involving a knife, staging the scene to look as though they had shot an intruder who was attacking the wife.

Defense attorney John Carroll argued that Magalhães’ testimony could not be trusted because she was cooperating with prosecutors to try to avoid a long prison sentence. In his own testimony, Banfield said that the testimony was “ absolutely crazy”.

Carroll also introduced evidence showing that there was dissent within the police department over the theory that Magalhães and Brendan Banfield impersonated Christine Banfield on social media in a “catfishing” scheme. 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.

In closing arguments, prosecutor Jenna 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.

The jury deliberated for nearly nine hours across two days before reaching a verdict. Banfield faces the possibility of life in prison at sentencing.

Magalhães was scheduled to be sentenced after Banfield’s trial. Attorneys have said she could be allowed to walk free if she is sentenced to time served.