Before joining the Bobcats, Thornton was on Boals' staff at Stony Brook as an assistant coach. In his two seasons with Stony Brook, Thornton was instrumental in player development, life skills, scouts and recruiting. With that assistance, Stony Brook finished second in the America East with a 24-9 overall record and helped Stony Brook to its most successful year in the Division I era. While at Stony Brook, Thornton helped the Seawolves to a postseason appearance in the 2019 College Basketball Invitational (CBI). With that assistance, center Jeff Otchere earned American East Defensive Player of the Year, Akwasi Yeboah earned American East First Team, Elijah Olaniyi earned American East Third Team and Miles Latimer earned American East Rookie Team.
Prior to Stony Brook, Thornton served as a graduate assistant and video coordinator at Toledo under head coach Tod Kowalczyk during the 2016-17 season. Thornton's responsibilities included player development, analytic breakdowns, video coordinator, assisting in organizing the program's annual summer camps and the coordination of the Rockets' community relations efforts. While at Toledo, Thornton helped the Rockets to 17 wins and a postseason appearance in the 2017 College Basketball Invitational (CBI). With that assistance, forward Steve Taylor, Jr. earned All-MAC Second Team honors after leading the nation with 9.9 defensive rebounds per game and ranking third nationally with 12.2 rebounds per contest. Additionally, guard Jonathan Williams received All-MAC Third Team accolades after ranking third in MAC scoring with 19.6 points per game.
A Columbus, Ohio native, Thornton spent the 2015-16 season as an assistant coach at one of the premier prep schools in the country, Hargrave Military Academy. Thornton helped Hargrave post a 47-1 record en-route to capturing its third national championship in school history.
Thornton's previous coaching experience also includes stints as a student assistant at Ohio Dominican (2011-14) and as an assistant coach for the Hilliard Davidson High School varsity program (2014-15). He graduated from Ohio Dominican University in 2015, where he earned a bachelor's degree in Sports Management and earned a master's degree in Recreation and Leisure Studies at Toledo.
Lamar is the son of Calvin and Valerie Thornton who currently live in Columbus, Ohio.