Karl has been involved with HIV/AIDS clinical trials and has been a community HIV/AIDS activist since 1993.

He was a member of the CCG (Community Constituency Group), now known as the GCAB for several years. When the Henry Ford Health Systems site was de-funded by the ACTG he remained involved with the ACTG and the GCAB and is a member of the CSS as a non-ACTG member. He continued to share the information with his local community and the prior CAB members of Henry Ford Health Systems. Karl was also one of the founding community members of the Ryan White Planning Council of Detroit. As part of his CSS activities Karl has served as a past CSS Co-Chair of the Under Represented Populations Sub-Committee, Adherence Intervention Working Group, Policy and Procedures Sub-Committee and the Community Partners Sub-Committee.

Karl participates in many HIV/AIDS activities in his community of Detroit, Michigan and is a clinical trial participant with the NIH for the past several years, including the Long Term Non-Progressors study.