Brendan Banfield is currently facing trial on charges of murdering his wife, Christine. The case’s key testimony comes from an unexpected source: the couple’s former nanny and Banfield’s lover.

Juliana Peres Magalhaes, who also faced charges, has agreed to testify against Banfield as part of a plea deal. Her cooperation will result in her pleading guilty to a reduced charge of manslaughter, allowing her to be released with time already served.

Following her release, Magalhaes will be deported to her native Brazil.

The tragic events began as Christine Banfield arranged a delightful outing for her 4-year-old daughter, planning a visit to the National Zoo. Accompanying them was the Brazilian au pair, Magalhaes.

Setting off for their day of fun, the outing was interrupted when Peres Magalhaes realized she had forgotten their packed lunches, prompting them to return home.

Arriving at the house, the au pair sees a car she doesn’t recognize, and a man she doesn’t know entering the house.

Confused, she calls her employer, Brendan Banfield, who tells her to stay in the car; he will be right home. Banfield is at the house in minutes, and they enter the house together.

The au pair takes the 4-year-old girl to the basement while Brendan Banfield goes upstairs to the master suite.

Brendan Banfield finds his wife, Christine, nude, with a man he doesn’t know, holding a knife to her throat. Banfield tells cops he tells the man to put the knife down, but he starts stabbing the 37-year-old mother.

Brendan Banfield carries a gun as an IRS Special Agent, and he draws his service revolver and shoots the man in the head. The intruder is wounded and down on the ground.

Banfield calls for Peres Magalhaes and tells the au pair to get his personal gun, a Glock, out of the bathroom safe.

Giving her the code, the au pair retrieves the Glock and, at Banfield’s direction, shoots Joseph Ryan through the heart as he is lying on the ground.

Investigators say, however, they believe the story told by Brendan Banfield and the nanny is a ruse.

Someone created the profile on the Adult Fetish website, pretending to be Christine Banfield, part of an elaborate plan to kill Christine Banfield so her husband, Brendan, and their Brazilian live-in au pair could be together.

Investigators found pictures of Banfield and the au pair together in the Banfield bedroom, and Peres Magalhaes’ clothes were found hanging in Banfield’s closet, not her own.

Joining Nancy Grace today:

Additional Guest

• Sydney Sumner  – Investigative Reporter, “Crime Stories”

“Crime Stories with Nancy Grace” on Fox Nation is also a national radio show on SiriusXM channel 111, airing for two hours daily starting at 12 p.m. EST. You can also subscribe and download the daily podcasts at iHeart Podcasts.

[Feature Photo: Christine Banfield/Handout]