Teresa Youngblut, a 21-year-old woman, pleaded not guilty to the murder of a U.S. Border Patrol agent on Jan. 20 of this year.
Friday was Youngblut’s first court appearance since prosecutors said they would be seeking a harsher punishment.
She is accused of shooting Agent David Mayland during a traffic stop in Vermont near the Canadian border after she was pulled over with Felix Bauckholt…