Banfield murder trial resumes Tuesday in Fairfax County

FAIRFAX, VA. - Testimony is set to resume Tuesday in the high-profile Fairfax County trial of Brendan Banfield, who is accused of killing his wife and another man, allegedly to continue a relationship with the family’s au pair.

What we know:

Prosecutors say Banfield and his au pair, Juliana Magalhaes, were in a romantic relationship and planned the killings together. They allege the pair used a fetish website to lure Joseph Ryan to the home, staged a fake home invasion and then killed both Ryan and Banfield’s wife, Christine.

Magalhaes, who originally faced murder charges, pleaded guilty to manslaughter and is now a key witness for the prosecution.

She testified last week that she and Banfield had an affair, that Banfield wanted to "get rid of his wife" and that they practiced shooting guns together. Prosecutors also allege Banfield spent $30,000 to upgrade the home’s windows to muffle sound.

The jury heard Magalhaes describe the night of the killings, as well.

Jurors also saw crime scene photos, heard the original 911 call and watched video of Banfield near a McDonald’s, which prosecutors say shows him waiting to return home and carry out the plan.

Defense questions witness credibility and forensic evidence

The other side:

Banfield’s defense team challenged Magalhaes’ credibility in court, pointing out that she has spoken with TV producers about her story and received financial help. The defense argued that her media conversations were a key reason she is working with prosecutors.

Magalhaes said keeping the truth inside was affecting her mental health. A forensics expert also testified that Banfield’s DNA was not found on the knife allegedly used to stab Christine.

Banfield has pleaded not guilty to seven counts. His defense team has a witness list, but it is unclear how many will be called.

What we don't know:

It remains unclear how many witnesses the defense will call or whether Banfield will testify.