Judge Margaret Miller was born in Islip, New York.  She attended West Chester University and earned her law degree from Dickinson School of Law. Judge Miller was elected to the Lancaster County Court of Common Pleas in 2007, and she was retained in 2017.  Judge Miller was instrumental in developing the Lancaster County Mental Health Court Program, over which she presided from its inception in 2010 until 2025.  Judge Miller presides over Criminal Court and handles various civil matters.