At a hearing and in court filings, a federal prosecutor in Vermont cited connections between the defendant, Teresa Youngblut, and people linked to other murder investigations.

The gun used in the shooting death of a Delaware County couple was used in connection with the line-of-duty shooting death of a border patrol agent in Vermont, officials said.

A Washington state woman who federal authorities say was involved in a shootout that killed a U.S. Border Patrol agent last week has been ordered held in custody while her criminal case remains pending.

The shooting on Monday in Vermont near the Canadian border followed the surveillance of an armed couple who dressed in black tactical-style clothing.

As the sprawling investigation unfolds, here’s an overview of the key figures involved and their alleged connections.

A Washington state woman was ordered held without bail Thursday in connection with the death of a U.S. Border Patrol agent in Vermont.