Jonathan Grusing
The Most Dangerous Behaviors and You

Bio: Jonny Grusing was a Special Agent (SA) with the FBI's Denver Division from 1996 to 2021.  For 23 years of his career, he worked violent crime matters to include missing persons, serial killers, federal jurisdiction homicides and mass attacks.  From 2008 until his retirement, he served as the Behavioral Analysis Unit (BAU) Coordinator for the division.  Former SA Grusing received extensive training from the profiling unit during these years and employed that training in addressing the serious violent crime cases in Colorado.  From 2013 through the present, he has taught hundreds of seminars on profiling serial killers and preventing mass attacks using the sound BAU principles.  In 2021, he became the Director of Security for the Douglas County School District in Colorado, where he remains today. Former SA Grusing now addresses the daily challenge of keeping over 63,000 students and 8,500 staff members safe in the 90 schools he supervises.  He works closely with four different law enforcement departments, building leaders and mental health support to prevent students from continuing down Pathways of Violence through a variety of measures.  

Former SA Grusing has appeared on numerous documentaries, to include 48 Hours, Dateline, 20/20, Hulu, Investigative Discovery, American Greed and Oxygen, along with numerous podcasts. In 2025, he authored "The Devil I Knew: Unmasking a Serial Killer," a book that documented his fifteen-year investigation into Scott Kimball, a convicted serial killer and FBI informant. 

  The Most Dangerous Behaviors & You
Summary: "The Most Dangerous Behaviors & You" will be an interactive discussion using case studies and a practical template to identify, assess and manage dangerous individuals - adults or youth. Former SA Grusing will share the tools he acquired from working with the FBI's BAU and from his personal experience in interviewing dangerous adults and students. The presentation will include: identifying the basic types of dangerous personalities; providing prototypical examples of dangerous people by examining serial killers, mass attackers or serial rapists; then learning how to interview and investigate persons who pose such threats in the most effective manner. Practical and teachable ways to collaborate with the persons of concern, and their stakeholders, will help attendees understand where these people are on the Pathway of Violence and what risk they pose. Tools will be provided on how to redirect violence away from the institution or organization being protected. Investigators, administrators and health providers will also learn what "mirror work" must be done internally for them to effectively interact with those who threaten society. 

The presentation will also address targeting, leakage, radicalization (largely through social media and the internet), and how warning signs vary with the differing types of violence.