Glamorous au pair, 23, is accused of elaborate murder plot that saw her boss turned lover's wife stabbed to death and a BDSM fetishist stranger shot dead beside her

An au pair has been accused of killing a BDSM fetishist as part of an elaborate plot with her IRS agent boss to get rid of his wife so they could be together.

Brazil native Juliana Peres Magalhaes, 23, is charged with the murder of Joseph Ryan, 39, who was found shot dead inside the $1million mansion of the family she worked for in Herndon, Virginia.

Christine Banfield, 37, was also found fatally stabbed after being attacked in her bedroom in February 2023. No one has been charged in her death.

Peres Magalhaes and Banfield's husband Brendan Banfield claimed they entered the home to find Ryan attacking Christine.

Brendan, a law enforcement officer for the Internal Revenue Service, told police he grabbed his service gun and shot and injured Ryan.

He told police he then ordered Peres Magalhaes to grab another gun and shoot him again, which she did and allegedly killed him.

But in a preliminary hearing on Monday, prosecutors said the evidence points to a different story, suggesting Ryan was gunned down as part of a confusing scheme to get rid of Christine so Brendan and Peres Magalhaes could be together romantically. 

Juliana Peres Magalhaes, 23, is accused of killing a BDSM fetishist as part of a plot with her IRS agent boss to get rid of his wife so they could be together

According to prosecutors, the au pair and her boss Brendan Banfield were having an affair, which detectives discovered when they returned to the home after the killings and found picture frames filled with photos of the now-couple in the bedroom where Christine died

Prosecutors say someone created a fake account for Christine on a BDSM site and made plans to have 'rough sex' with Ryan before they were both killed. 

The mom reportedly did not sound like herself in her alleged conversations with Ryan, leading police to believe someone else was pretending to be Christine and set up a meeting at the home on the day of the killings.

According to prosecutors, the au pair and her boss were having an affair, which detectives discovered when they returned to the Banfield home after the killings and found picture frames filled with photos of the now-couple in the bedroom where Christine died. 

Detectives also said they found the au pair's lingerie around the room, describing her as Brendan's 'live-in lover.'

Mother-of-one Christine Banfield, 37, was also found fatally stabbed at the scene in her home after being attacked in her bedroom in February 2023. She is seen with husband Brandon

Joseph Ryan, 39, was found shot dead inside the $1million home. Prosecutors sugges

Brendan was questioned about his relationship with Peres Magalhaes in court Monday but invoked his Fifth Amendment right.

Prosecutors also say Brendan and the au pair went to a shooting range together months before the alleged home invasion, and that Brendan later returned to buy a gun. The pair is also accused of swapping out their phones for new ones in the days before the killings. 

Peres Magalhaes told police she left the family's home with the Christine's four-year-old daughter the morning of the murder to go to the zoo, but returned shortly after because she had forgotten to grab packed lunches.

The au pair said she noticed a car she did not recognize in the driveway when she returned, and tried calling Christine, who did not pick up the phone. She then supposedly called Brendan, who quickly arrived at the scene.

Prosecutors say someone created a fake account for Christine on a BDSM site and made plans to have 'rough sex' with Ryan before they were both killed at the upscale home

Detectives also said they found the au pair's lingerie around the room, describing her as Brendan's 'live-in lover'

When the pair and the girl entered the home, Brendan reportedly went to the bedroom and found Christine and Ryan in a struggle.

Peres Magalhaes and Brendan told police Ryan had attacked Christine so Brendan fired his service weapon. They said they had no connection at all to the alleged intruder. 

Peres Magalhaes was arrested almost eight months after the killings and charged with second-degree murder for shooting Ryan.

Her lawyer has said she had a sexual relationship with Brendan but it was not exclusive, adding that the married couple supposedly were both unfaithful to each other.

No one has been charged with Christine's death. 

Fairfax County Police Chief Kevin Davis has said she expects more people to be charged in the killings.