IRS agent Brendan Banfield charged with murdering wife Christine and au pair in Virginia double homicide

In 2023, IRS agent Brendan Banfield claimed he shot a stranger to stop the man from stabbing his wife Christine in their Virginia home, but police determined Banfield himself committed the double homicide and shot the au pair he was having an affair with. Investigators found Banfield's account inconsistent with evidence and discovered his secret relationship with the family's au pair provided motive for the killings. The case exposes how initial self-defense narratives can mask premeditated violence and how affair-driven motives drive family murders. NBC's Dateline investigated and interviewed reporters Andrea Canning and Blayne Alexander about the investigation findings.