On Monday's episode of "Elizabeth Vargas Reports": There was a major meeting about Venezuela at the White House amid scrutiny over military strikes against alleged drug boats. Then, a pivotal hearing for Luigi Mangione, the man accused of shooting UnitedHealthcare CEO Brian Thompson, in Manhattan. In Massachusetts, Monday saw the start of a murder trial for Brian Walshe, who's accused of killing his wife. #Venezuela #LuigiMangione #BrianWalshe