FAIRFAX, Va. (CN) - Infatuated with the family's Brazilian au pair, Brendan Banfield plotted to get rid of his wife and kill a stranger who had been lured to the Banfield residence as part of an alibi, prosecutors told a jury during the first day of trial in the double murder.

Dressed in a black suit, Banfield, 40, wept as prosecutors played recordings of the 911 calls he and the au pair made to authorities as his wife, Christine, 37, was in the process of dying from multiple stab wounds. He has pleaded not guilty to aggravated murder, along with child abuse and endangerment charges stemming from the presence of his then 4-year-old daughter the day of the crime.

In opening arguments, Chief Deputy Commonwealth's Attorney Jenna Sands said Banfield did not want to share custody of his daughter with Christine. Instead of a divorce, he planned to kill her.

"He talked about hiring a hitman, finding someone to kill her for money, but he was concerned that that would tie back to him, that there would be too much evidence against him, and he could be at risk," Sands asserted.

Banfield, along with the au pair, Juliana Peres Magalhaes, crafted a different plan, Sands added. "They would use Christine's email accounts to create a fake profile to lure someone in who was into kinky sex, violent sex. And they would get this guy to come into the house and fake rape Christine. Brendan would be the hero of the day. He would show up, kill the guy."

Using a fetish website, Banfield and Magalhaes spent weeks talking to potential victims before finding Joseph Ryan. In exchanges online, Ryan thought he was talking to an attractive woman new to kink, Sands said.

"Brendan created the narrative that Christine desperately wanted to be raped. Posing as Christine, [Banfield] told Joe what to do," Sands explained. Ryan was to come to the Banfield home in Reston. The door would be unlocked. Christine would be asleep in bed.

"Come straight upstairs, cut off her clothing, tie her, rape her - simple and fun. That was how it was posed," Sands said. Ryan was also told he was not to stop, even if she looked terrified and was calling for help.

They planned this for Feb. 24, 2023. On that morning, Banfield hid his wife's telephone so she couldn't call for help.

Banfield left the house and went to a McDonald's. Magalhaes got in the car and drove to a cul-de-sac. She had a gun in her pocket, and the couple's daughter was in the back of the car. Once Magalhaes spotted Ryan headed for the house, she called Banfield and alerted him, Sands said.

Ryan and Magalhaels then returned to the house. Leaving the child in the basement, the two went up the stairway. "Brendan enters the bedroom first, shooting Joe in the head, [then] picks up the knife that Joe had brought, and stabs Christine repeatedly in the neck. He directs Juliana to shoot Ryan a second time with her gun."

As his wife was dying, Banfield staged the bodies.

John F. Carroll, Banfield's lawyer, offered a different narrative. The case against Banfield was built upon a statement made by Magalhaes, he argued. Initially charged with murder, she pleaded to a reduced charge of manslaughter after giving the statement.

"As the case went on, it became clear that they wanted him so badly that they were willing to do anything. They made offers," Carroll said.

At one point, Magalhaes said she was being asked to say something that wasn't true, Carroll recounted. Police arrested Magalhaes nearly a year before Banfield. "He was the person on the outside who she was really depending on. They had an affair. You're not going to get any arguments from us. But he played a supportive role to her while she was in jail.'

With his arrest, Magalhaes became more vulnerable. "[Investigators] tried their little experiment on what she would take to come forward and tell a story," Carroll argued.

One of the detectives in the case was transferred because the digital forensics investigator's findings did not support the "catfish theory."

"I was a prosecutor myself in Fairfax. I've never experienced a homicide investigation where the lead homicide detective was moved prior to a trial," he added.

During the first day of testimony, the courtroom was full for the high-profile trial presided over by Penney S. Azcarate, chief judge of the circuit court in Fairfax County, Virginia. 

Source: Courthouse News Service