Prosecutors alleged in court on Monday that Juliana Magalhaes and Brendan Banfield had been having an affair at the time of Christine Banfield's murder.
Brendan Banfield told police that he arrived at his Virginia home on the morning of Feb 24., 2023, to find his wife, Christine, naked and a man holding a knife to her throat.
The family's Brazillian au pair called Brendan just minutes before when she saw a mystery man, later identified as 39-year-old Joseph Ryan, walk into the house, he explained to officers with the Fairfax County Police Department (FCPD) when they arrived on the scene.
He and the au pair, 23-year-old Juliana Peres Magalhaes, both alleged that once inside the home, they went upstairs to the master bedroom where they found Christine being stabbed by Ryan.
Brendan shot Ryan in the face and then instructed Magalhaes to retrieve his other gun from a safe, claimed Magalhaes.
She returned with the gun and shot Ryan, who police declared dead at the scene. Christine would die a few hours later after being rushed to the hospital.
Magalhaes called authorities with Brendan also on the phone, according to dispatch. Brendan admitted to firing the first shot at Ryan while Magalhaes shot him the second time, though she later told police she did not know if that bullet ever hit the man.
Both later told officers that they were acting in self-defense at the time.
Nothing happened with the case for the next eight months, and Magalhaes continued to work as the au pair to Brendan's 4-year-old daughter after Christine's death.
Then. on Oct. 19, police arrested Magalhaes on a charge of second-degree murder.
That charge related to the murder of Ryan, with law enforcement and prosecutors both saying that the initial shot to the head he sustained when Brendan fired at him would have left him incapacitated, so Magalhaes had no reason to fire the second bullet.
The medical examiner said it was the second bullet that killed Ryan.
Then, just this week, a new development in the case as prosecutors appeared in court and made several shocking allegations.
Prosecutors alleged in court on Monday that Magalhaes and Brendan had been having an affair at the time of Christine's murder.
They also allege that Christine met Ryan on a bondage and sex fetish website, but do not believe that Christine is the one who contacted him based on the syntax and tone of the emails exchanged by the pair.
Prosecutors also said that Brendan and Magalhaes traveled to a shooting range in the months before the murders and that Brendan purchased a new gun.
Brendan and Magalhaes also swapped out their cellphones for new ones just before the murders, said prosecutors.
Prosecutors also said at the hearing on Monday that when investigators arrived at Brendan's house in October before Magalhaes' arrest, they found a photo of the pair on Christine's nightstand and the au pair's lingerie scattered around the bedroom.
Brendan briefly took the stand on Monday but invoked his Fifth Amendment right for most questions.
The judge ultimately ruled that enough probable cause existed for the proceedings against Magalhaes to move forward, and it is expected that a grand jury will hear evidence in the case later this month.
Her attorney did not respond to a request for comment but has previously said this client shot Ryan in self-defense.
Prosecutors and police say that the investigation into Christine's death is ongoing.
