Don is a retired Detective-Sergeant from the City of Vallejo in California's San Francisco Bay Area. During his law enforcement career, he specialized in crimes against persons, with a focus on homicide and suspicious death investigations. Recognized as a subject matter expert by California POST, Don also served on several specialized teams, including the Hostage Negotiations Team, the Field Training Unit, the Solano County Sex Offender Task Force, and the Officer-Involved Fatal Incident Investigation Team.

 

Following his retirement, Don relocated to Connecticut and, in 2008, joined Quinnipiac University as the Director of Investigations for the Department of Public Safety. In this role, he leads the Investigations Unit and collaborates closely with Student Affairs, Human Resources, and local, state, and federal law enforcement partners. Don is a member of the University's Threat Assessment and Emergency Management Teams, an Active Assailant Awareness Instructor, a former Title IX Investigator, and currently holds the rank of Captain.

 

In 2011, Don founded Madison Investigative Services, LLC, providing investigative support to clients across a wide range of sensitive and complex matters. His work has included personal and workplace investigations, wrongful death and fatal accident cases, missing persons, and allegations of abuse and neglect involving individuals with developmental disabilities.

 

Don was featured as the Investigative Consultant for the HBO four-part documentary series Murder on Middle Beach, which premiered in November 2020. The series explores the 2010 unsolved murder of a Connecticut woman and follows the victim’s son as he seeks answers. Don played a key role in guiding the investigation and providing professional insight throughout the series.

 

In 2020, Don became the President of the Connecticut Private Investigators Association (CPIA), a role in which he continues to serve today, leading the organization's ongoing efforts to professionalize and elevate the standards of private investigation services throughout Connecticut.

 

Most recently, he appeared in This is the Zodiac Speaking, a Netflix documentary released in October 2024. Don's involvement with the Zodiac investigation began in the late 1990s when he served as a detective with the Vallejo Police Department and took on a leadership role in the Zodiac Task Force.

 

A U.S. Marine Corps veteran with service in the Military Police, Don holds a bachelor’s degree in Management from Saint Mary’s College of California and a master’s degree in Organizational Leadership from Quinnipiac University.