Gary has worked in the Scottish Ambulance Service since 1999, as a frontline paramedic, educator and latterly as the National Patient Safety Manager. In this role, Gary was the ambulance service representative on the Scottish Government Drug Death Task Force. He led the implementation of the ambulance service drug harm reduction team in 2021, which resulted in the establishment of a national data sharing agreement between the ambulance service and territorial health boards, roll out of a programme that enables all ambulance clinicians in Scotland to provide Take Home Naloxone, and implementation of education and development opportunities for ambulance staff related to stigma, drug and alcohol use, and referral pathways.

Gary is currently on a 2 year secondment as Senior Lecturer at the University of Stirling, where he teaches paramedic undergraduate students, and is also involved in soon to be published research related to ambulance response and clinician experiences of attending emergency calls for possible overdose.