He gave nearly 30 years of service to the Sacramento community. During his career, Gary spent three tours of duty in Internal Affairs and over ten years as the commander of the Sacramento Police Department's hostage negotiations team.

During his stint as negotiator commander, Gary responded to over 200 critical incidents, such as barricaded subjects, suicidal individuals, and hostage takings. Lt. Gregson was a patrol division watch commander and has commanded dozens of critical incidents. Gary is the founder of the popular crisis negotiator training web site: NegotiatorCentral.com

Gary has taught critical incident response and management to hundreds of law enforcement officers and managers across the country. He is currently training and consulting on both topics of Critical Incident Response and Internal Affairs for both police and fire service organizations. Gary recently developed a very popular course being presented nationwide, "Officer Involved Shootings for Field Supervisors", which addresses the practical responsibilities of supervisors responding to such challenging, trying and often tragic events. As well, Gary and his staff of highly experienced presenters have produced courses on Domestic Violence when officers are involved and when crisis negotiators are called to duty. Each situation delivers uniques challenges to crisis repsonders worldwide.