Dexter was born and raised in Edmonton, Alberta. He attended the University of Saskatchewan where he played running back for four years while studying Psychology and Sociology. Dexter then competed for the Okanagan Sun for one season as a free safety before being drafted by the Calgary Stampeders in the 2015 CFL draft. Dexter was the first athlete to represent the Okanagan Sun at the CFL national combine. During his time with the Calgary Stampeders, he competed in two Grey Cups and one western final. In 2019, Dexter was a member of the Grey Cup Championship winning Winnipeg Blue Bombers team.
In 2018 Dexter competed with the Team Canada 4-man Bobsleigh team as a brakeman on the World Cup circuit. Dexter joins the Rebels as the Defensive and Special Teams coordinator