ABOUT OUR INVESTIGATIVE TEAM
Our investigators are licensed annually by the Montana Board of Private Security, within the Montana Dept. of Labor and Industry. Mark Fullerton is also licensed as an investigator in Alaska.

Mark Fullerton
Mark Fullerton began his professional private investigator career operating primarily in the area of Northern California known as the Emerald Triangle and constituted by Mendocino, Humbolt and adjoining counties. Mark obtained a bachelor’s degree in Sociology from the University of Montana and relocated to Monterey, California to resume his career in private investigation. Mark gained extensive experience in the investigation of a variety matters in both the criminal and civil arenas. His work included two death penalty cases and several major personal injury law suits.
In 1993 Mark returned to Missoula, Montana. Since that time he has acquired a reputation for diligence and professionalism, and is respected by his clients, colleagues and people in the justice system on all sides. He has a distinguished unblemished reputation, and he has established a national presence.
Mark has extensive experience in locating individuals, researching backgrounds, surveillance and interviewing witnesses. He has worked closely with lawyers, experts and parties in formulating litigation strategies. He has experience working with experts in handwriting analysis, crash scene reconstruction, forensic entomology, sentencing mitigation, crime scene reconstruction, polygraph and pathology.
Mark recently assisted, as a lead investigator, the legal team retained by Brigadier General Jeffery Sinclair in a court martial case referred to by The New York Times as “The most important sexual assault prosecution in the military…” Mark assisted the late Kelly Clark in the civil prosecution of several Boy Scout leaders, throughout the country, for sexually assaulting scouts. In addition, Mark was the lead investigator for the defense team retained to represent a defendant in an international drug conspiracy case involving Columbia, Ecuador, Canada and the United States. Mark also participated in a matter under the Antiterrorism and Effective Death Penalty act of 1996.
Mark is licensed in Montana and Alaska. He has international clients and associates, as well as access nationally and internationally.
Dan Dunlap
Dan Dunlap joined Mark Fullerton Investigations in 2019. Dan is a retired Special Agent of the Drug Enforcement Administration, where he worked for over 27 years, with the last 20 years investigating cases all over Montana. His experience is diverse, but he specializes in witness interviews, surveillance, and complex investigations. Dan has developed numerous contacts within and outside of law enforcement all over Montana and throughout the United States, and he strives to employ all available assets to uncover details within any investigation.
Dan is a recognized expert in state and federal court, and has countless hours of experience testifying in all levels of hearings and in front of juries. In trial preparation, Dan has a unique ability to prepare witnesses for trial testimony. He also has an excellent reputation with state and federal judges, prosecutors and defense counsel alike.
Dan is a graduate of Marquette University (1987) with majors in Political Science and Spanish, and he graduated from Montana State University-Billings (2015) with a Master of Public Administration degree. He is also a small business co-owner with his wife of 31 years, and he is the father of three grown children and the grandfather to three grandsons.
Dan resides in the Billing area and is available for investigations throughout the region.
