About

Andrew Greydanus is the owner and lead investigator of Greydanus Investigations LLC, based in Billings, Montana. With a strong background in military service, law enforcement, and criminal defense investigations, he brings a disciplined, detail-oriented approach to every case.

Andrew began his career in the Montana National Army Guard, as an Indirect Fire Infantryman, serving in Operation Iraqi Freedom. Over the course of his military career, he advanced into leadership roles including Squad Leader and later transitioned into Military Police, where he continued to develop his expertise in law enforcement operations, supervision, and security. He also served in Operation Enduring Freedom, gaining valuable real-world experience in high-pressure environments.

During his military service, Andrew built a solid foundation in civilian law enforcement, serving as a Patrol Deputy with multiple sheriff’s offices across Montana, including Yellowstone, Wheatland, and Sweet Grass Counties, as well as with the Billings Logan International Airport Police. During this time, he held specialized roles such as Firearms Instructor, K-9 Handler, Evidence Technician, and Reserve Deputy Coordinator. His work provided extensive experience in investigations, evidence handling, report writing, and courtroom testimony.

Andrew later transitioned into criminal defense investigations, working as a Criminal Defense Investigator II with the Office of Public Defenders. In this role, he conducted in-depth case investigations, witness interviews, mitigation reports, and evidence analysis to support defense attorneys and ensure thorough case preparation.

He holds a Bachelor of Arts in Law Enforcement Administration, graduating summa cum laude with a 3.90 GPA, and a Master of Business Administration in Human Resource Management with a 3.92 GPA. His formal education is complemented by different trainings such as investigative techniques, digital forensics, social media investigations, and legal procedures.

Andrew is a licensed private investigator and process server in the State of Montana, and a member of professional organizations including the National Association of Public Defenders and the National Defender Investigator Association. His certifications and ongoing training reflect a commitment to staying current with modern investigative practices.

Throughout his career, Andrew has earned multiple military commendations, including four Army Commendation Medals, recognizing his leadership, professionalism, and dedication to service.

Today, as the owner of Greydanus Investigations LLC, Andrew is committed to providing discreet, professional, and results-driven investigative services. His combined experience in military operations, law enforcement, and defense investigations allows him to approach each case with a unique perspective and a strong commitment to uncovering the truth while maintaining the highest standards of confidentiality and integrity.