A man accused of carrying out an elaborate fetish sex plot to kill his wife and a man inside his Northern Virginia home is set to stand trial.

Nine men and seven women were selected to the jury Monday in the trial for Brendan Banfield. Four of those 16 jurors are alternates who will step in if other jurors can’t attend for some reason.

Banfield is charged with aggravated murder in the killings of his wife, 37-year-old Christine Banfield, and a stranger, 39-year-old Joseph Ryan, at the Banfields’ Herndon home on the morning of Feb. 24, 2023.

Prosecutors say Brendan Banfield was having an affair with the family’s au pair, Juliana Peres Magalhães, for months before the killings, and that he conspired with his then-4-year-old daughter’s caretaker to get his wife “out of the picture.”

Peres Magalhães told prosecutors Brendan was the mastermind of the alleged plan. She said he created a fake profile on FetLife.com, a kink, BDSM and fantasy dating website, pretending to be Christine. Peres Magalhães said she and Brendan logged onto Christine’s work computer and used the fake FetLife account to solicit a stranger, Ryan, to the house to carry out a rape fantasy involving a knife.

When Ryan showed up to the house and started carrying out the plan, Brendan Banfield and Peres Magalhães burst into the bedroom pretending to save the day, prosecutors said. Banfield allegedly shot Ryan and then stabbed Christine.

Peres Magalhães said in an interview with prosecutors that she also shot Ryan. She pleaded guilty to manslaughter and spoke to prosecutors as part of her plea agreement.

The Fairfax County man accused of murdering his wife and another man in their home will stand trial starting Monday. News4’s Aimee Cho shares what to expect.

Banfield has denied the allegations. Defense attorneys argued in a hearing last summer that investigators have a secret folder of evidence that dismantles the so-called “catfish theory” that Brendan Banfield created the FetLife account.

A Fairfax County detective trained in digital forensics testified that he pulled and analyzed all the digital data on the devices used to access the FetLife profile. It was his professional conclusion that it was Christine on the computer, not Brendan, he said.

He said during a July 10 hearing that police command staff disagreed with his findings because they didn’t support their theory that Brendan Banfield was behind the fetish site profile.

The detective said his supervisors reassigned him off of the case against his will.

Multiple Fairfax County Police Department employees said under oath that the evidence did not support the theory that Brendan Banfield catfished Ryan to the family’s home.

Opening statements are expected to begin Tuesday, and the trial could take about four weeks.

News4 is getting rare, video access inside the courtroom. Watch a daily livestream of the trial and follow updates here and on the NBC4 Washington YouTube.