A Washington state woman has been ordered to be held without bail in connection with the death of a U.S. Border Patrol agent in Vermont.

The California suspect was listed on a marriage application with a woman accused of killing a Border Patrol agent. They attended Seattle's Lakeside School.

A man accused of murder in California appears to have sought a marriage license with a woman charged in connection with the fatal shooting of a U.S. Border Patrol agent in Vermont.

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.

Federal prosecutors say a Washington state woman charged in connection with the fatal shooting of U.S. border patrol agent in Vermont had been in frequent contact with someone whom authorities have linked to homicides in Pennsylvania and California.

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

Teresa Youngblut, 21, faces federal firearms charges in the Jan. 20 death of U.S. Border Patrol Agent David Maland, and police and court records have shed some light on connections to killings in othe