The woman accused of killing U.S. Border Agent David Maland allegedly used a gun bought by someone who was a person of interest in a double murder, prosecutors said.

Teresa Youngblut, 21, from Washington state, has been charged with two weapons-related offenses in connection to the death of 44-year-old U.S. Border Patrol agent David Maland. The agent was killed last Monday during a shootout in Coventry, Vermont, a small town located about 20 miles from the Canadian border.