Gary was born in Pittsburgh, PA where he attended an Episcopal elementary school called St. Edmund's Academy. He considers himself a cradle Episcopalian, growing up at St. Stephen's Church in Wilkinsburg, Pennsylvania.

Gary received his Bachelor of Arts in English from Yale College in New Haven, Connecticut graduating Magna Cum Laude with Distinction in the Major. He received his Master of Education from the Harvard Graduate School of Education in Cambridge, Massachusetts. Gary received his Master of Divinity from Virginia Theological Seminary in Alexandria, Virginia.

Gary worked as Assistant Head of School (among other things) at Wooster School in Danbury, Connecticut, serving for 17 years. This is where he heard his call to seminary, while serving as the school's chaplain as a layperson. He was a Director of Calvary Camp, in the Episcopal Diocese of Pittsburgh, and later served as a chaplain as an ordained person at St. Anne's Episcopal School in Delaware, right before coming to Trinity.

Gary came to Trinity in 2014, as the new Head of School. He and his wife Karen have been married for more than 30 years. They have three children, Charlie, Wendy, and Theo; Theo attended Trinity School for grades 6 - 8.  In his free time, Gary plays and teaches bridge, plays golf (badly!), and loves movies, reading, and strategy board games.