Au pair pleads guilty to manslaughter in gruesome murder of employer's wife

A Virginia au pair pleaded guilty Tuesday to manslaughter in connection to the 2023 murders of her employer's wife and another man.

Juliana Peres Magalhaes' employer, Brendan Banfield, was charged with murder last month in the case -- a year after Magalhaes was arrested and charged.

Prosecutors said Magalhaes and Banfield began an extramarital affair in August 2022, and by the fall of that year, Banfield expressed his desire to "be rid of" his wife, Christine Banfield, according to the plea agreement obtained by ABC News.

Throughout the months that followed, Brendan Banfield would allegedly flesh out this plan, according to the prosecution. However, Magalhaes did not want to continue with at several points, prosecutors said, and allegedly did not believe Banfield would follow through with it, according to the plea agreement.

In the leadup to the double murder, Brendan Banfield allegedly created a profile on the sexual fetish site FetLife, where he found a man named Joe Ryan, the plea agreement details. He then allegedly had Magalhaes call Ryan, pretending to be Christine Banfield, to confirm both were willing to engage in sex at her home with the use of "restraints," according to prosecutors.

When Ryan arrived at the house in February 2023, Banfield allegedly shot him in the head and then stabbed his wife to death, according to the prosecution agreement. Magalhaes then also shot Ryan, prosecutors said.

Magalhaes then allegedly called 911 and pretended Ryan had been an intruder, prosecutors said.

Magalhaes initially faced second-degree murder charges in connection to Ryan's death. On Tuesday, Magalhaes pleaded guilty to a reduced charge of manslaughter.

She could face up to 10 years in prison.

Her sentencing is scheduled to take place on March 21 after Banfield's February trial.

"Today's agreement marks a significant step forward in this case, and it is an important development in our pursuit of justice for the victims and their families," Fairfax CountyCommonwealth's Attorney Steve Descano said in a statement read outside the courthouse. "Much of the information that led to this agreement cannot be made public at this time due to the upcoming criminal trial against the other defendant in this matter."

ABC News' Cristina Corbin, Briana Stewart and Gemma Schneider contributed to this report.