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 search warrant, filed by Vermont State Police for Pennsylvania State Police, was executed in connection to the double homicide of Michelle Zajko's parents.

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.

The weapon that killed Agent David Maland last week in northern Vermont was bought by a person of interest in a double murder two years ago in Delaware County, state police say.

Investigators are exploring whether two apparently unrelated murders could be linked, by way of an alleged cult made up of highly educated computer scientists with an interest in animal rights, Andrea

One suspect, a German national, is dead, and a second suspect, a U.S. citizen, suffered injuries, authorities said.

Agent David “Chris” Maland died in a shooting following a traffic stop, the FBI said. A second person killed in the incident was a German national in the country on a current visa, authorities said.