Sean B. Dennis

Bomb Squad CDR, Ret.

Executive Director 


Sean Dennis is a Hazardous Devices School (HDS) graduate and was a former Bomb Squad Commander/Special Operations Sergeant. He spent 13 years on the SWAT Team and was fortunate to  simultaneously be on two specialized units.  Other then supervising the Bomb Squad and HAZ-MAT Teams Sean was the Assistant Emergency Manager for one of the largest counties in Colorado and a state certified HAZ-MAT Technician.  He has been involved in the Bomb Technician/Explosive community for over 19 years (26 Years Law Enforcement) and has been involved in many critical incidents which has formed his belief system and support for Military and Public Safety Bomb Technicians. Sean feels strongly in supporting this great community and has reached out to those with in the military and public safety ranks to listen and learn on what they are hoping to see in an organization like the USBTA. Sean has spent much of his time helping other organizations who have supported other Bomb Technicians who were in need of help and supported training events between Military and Public Safety Bomb Technicians. He has formed great partnerships with many from the military and public safety communities and hopes to bring these two groups together in a strong viable partnership.

SGT. Jon Vaala

Active Bomb Technician



Jon is a 20 year Colorado County Sheriff’s Office veteran and graduate of the FBI’s Hazardous Devices School. He has spent nearly 18 years on the Bomb Squad and is currently a Team Leader. In addition to being the Senior Technician, a “Tactical Bomb Technician” and a SWAT Breacher, Jon is passionate about supporting the EOD and his Public Safety Bomb Technician community. Being involved in multiple high-profile incidents and events over his 18 years has motivated Jon in his mission to promote cooperation and collaboration amongst the bomb technician community. His goal is to facilitate SWAT EOD integration, as well as the professional cooperation between EOD, the Public Safety communities, and equipment manufactures through the assistance of the USBTA.

Colonel Dean Meinert US Army, Ret.

Vice President


Dean Meinert, Colonel US Army (retired), recently served as the Chief, Humanitarian Mine Action and Explosive Ordnance Disposal while assigned to the Under Secretary of Defense for Policy. A career Explosive Ordnance Disposal Officer, he served in EOD assignments through Battalion Command. He has worked Counter-IED and Counter-WMD specialties and conducted operations in over 30 foreign nations. Dean deployed in support of OPERATION JOINT ENDEAVOR (Bosnia 1996), OPERATION ENDURING FREEDOM (Afghanistan 2002), OPERATION IRAQI FREEDOM (Iraq 2004-2005), OPERATION NEW DAWN (Iraq 2010-2011). He has a passion for the community and its’ operators. He recognizes the value in bringing our military and civilian technicians together into a single community of interest so that we may learn from, serve with, and share the successes and burdens of our profession in order to lighten everyone’s load.

Christopher A. Rogers

Bomb Squad Commander

Director of Operations


Christopher A. Rogers is a Pima County Sheriff’s Department Sergeant and the bomb squad commander for the Pima Regional Bomb Squad in Tucson, Arizona. Sgt. Rogers is a 25-year police veteran and 15-year bomb technician with experience in counter IED operations, Homemade Explosives operations, border operations, dismounted bomb squad tactics, and tactical integration of bomb technicians. He has extensive operational experience in HME investigations, and dismounted operations along the U.S.-Mexico border. He was one of the first bomb technicians in the United States to become a nationally certified Tactical Bomb Technician by the FBI. He played a lead role in the development of the National Tactical Bomb Technician Certification Course.

He sits on the National Bomb Squad Commander’s Advisory Board, which acts as the leadership element for the state and local public safety bomb squad community. He also chaired the Technical Support Working Group’s Southwest Border Counter IED Working Group, which coordinated between the DoD and Southwest Border Public Safety Bomb Squads. Sgt. Rogers instructs nationally and internationally. He has been a senior lead instructor for both federal, local and private sector entities for ten years and has received six weeks of advanced training from the Israeli National Police, which included a two-week imbed in Tel Aviv, providing a firsthand look into Israeli tactics and techniques. As a Department of State Antiterrorism Assistance Program Instructor he has instructed courses in Abuja, Nigeria, Manilla, Philippines, Jakarta, Indonesia, Mindanao, Philippines, Denpasar, Indonesia and Yaoundé, Cameroon. He has also provided courses of instruction in Veracruz, Mexico and in Cha’am, Thailand.

Chris’ goal is to continue to promote interoperability between military EOD and public safety bomb technicians which he found to be invaluable in efforts in Arizona, to continue the focus on SWAT and EOD integration and bomb squad dismounted operations nationwide, and encourage relationships across the career field.

Robert  VonLoewenfeldt

Active Bomb Technician

Director of Advisors 

Rob started his law enforcement career as a US Army Military Police Officer in 1993; after 5 years of active duty he moved on to civilian law enforcement.  In 2002 he joined the Chatham County Police Bomb Squad, which later became the Savannah-Chatham Metropolitan Police Bomb Squad.  He took command of the squad in 2006 and shortly after became the Southern Technician representative to NBSCAB.  Rob left SCMPD in 2013 for a job with the South Carolina Law Enforcement Division (SLED) Bomb Squad.  His duties with SLED include functioning as a SWAT operator, a K-9 handler, and a diver for the Maritime Response Unit.  In addition to over 14 years as a FBI certified bomb technician, Rob is also a lead instructor for the FBI’s Maritime Bomb Technician Program, a member of the DHS’s First Responder Response Group, the Combating Terrorism Technical Support Office’s IDD/EOD-LIC subgroup, and the National Institute of Standards and Technology’s ASTM Robotics group.  He has published several FBI Special Technician bulletins and, developed the national testing standards for underwater robots.

Rob is passionate about bomb squad integration with tactical teams, public safety dive teams, and US Military partners.  Rob also consistently works with industry to develop innovated tools, tactics and techniques to assist in closing operational gaps in bomb squad capabilities. 

SGT. Brian Knudsen 

Active Bomb Technician

Director of  Public Relations 


Brian is a 17-year Colorado County Sheriff’s Office veteran and a graduate of the FBI’s Hazardous Devices School. He has spent nearly 13 years on the Bomb Squad where he has been involved in high-profile incidents. It is these experiences and the tight knit community of Bomb Technicians that inspire him to want to provide support and training to Bomb Squads around the country. Brian recognizes the many obstacles Bomb Squads across the nation encounter such as costly training and constrained department budgets. His goal is to raise awareness to private entities about these obstacles in order to build financial partnerships which support USBTA’s training mission and contribute to the safety of their communities.

LT. Chris Hall

Bomb Squad Commander

Director of Public Safety Relations


A 17 year veteran with the Orange County Sheriff's Office FL and graduated of the FBI’s Hazardous Device’s School. He has spent 9 years on the bomb squad and is currently the commander of the team. Along with his commander duties he is a certified tactical breacher along with underwater post blast investigator and underwater renders safe techniques. Archilochos once said “We don’t rise to our level of expectations; we fall to the level of our training.” Chris believes that training is one of the most important things that a team can do to perform at a high level in any situation. Chris and his team were involved in the Pulse Night Club terror attack and it was because of his team’s high level of training that they performed so well that night. When an event like this occurs you may need the assistance of other members of the EOD community. That is why he believes that it is important to bring members of the EOD community together to train and learn from each other’s experiences, both military and public safety.

Peter Nagel, P.C.

Chief Counsel


Peter Nagel is a lawyer whose practice, located in Denver, Colorado, has included assisting nonprofit organizations with a wide variety of tax, corporate, and commercial law matters, including board and officer governance responsibilities, mergers and corporate restructurings, participation in tax-exempt financings, unrelated business taxable income issues, and the implementation of endowments and planned giving programs.

His diverse client base includes –

  • community foundations, supporting organizations, and corporate and private foundations
  • organizations that own and operate affordable housing nationwide
  • state, national, and international trade associations
  • religious organizations of all denominations
  • organizations engaged in political and legislative advocacy, and
  • a wide variety of charities engaged in education at all levels, the prevention, treatment, and cure of diseases, arts and culture, amateur sports, environmental protection, scientific research, and services to the elderly, the needy, and the underprivileged

1SG David A. Grotkin
US Army (Ret)

Director of Industry and Academia


A career Explosive Ordnance Disposal Non-Commissioned Officer, he served in many EOD assignments throughout his 20 year career. He conducted multiple combat operations in both Afghanistan and Iraq while supporting both conventional and special operation’s counter IED missions. While not deployed, David supported state and local public safety on numerous EOD incidents throughout the United States.

David’s goal is to bring both public safety and military bomb technicians together to learn from each other. He feels strongly about training and equipment and, understands that his community can only benefit from excellent training and great equipment. He believes that the joint experience from these two communities can only make them stronger and lead to a lasting partnership.

CSM Scott Weimer

US Army, Ret.

Director of Military Relations


     CSM Scott Weimer served in the US Army for 25 years; initially as an Airborne Infantryman, then volunteering for EOD.  For the last 21 years, he has served in every leadership position from Team Leader to Command Sergeant Major including Joint Staff positions, Special Operations, and direct support to Other Government Agencies.  Scott has multiple combat deployments to both Iraq (2) and Afghanistan (2), as well as numerous operational deployments to Egypt, Nigeria, Tunisia, and Qatar. 

     During his more than 21 years of EOD experience, Scott has worked closely with our Local, State, and Federal LEOs in matters ranging from routine off-post recovery of military ordnance, Counter-IED, Counter-WMD, Education, Counter-Narcotics, and VIP Protection.  He hopes to bring these experiences to the table and strengthen the bonds between Public Safety Bomb Technicians and Military EOD while working to raise awareness of our community; its complexity, its hazards, and the sacrifices that are made in service to our communities, at every opportunity.

  He is currently a full time Nursing student at the University of Colorado/Colorado  Springs working towards his MSN to become a Nurse Practitioner.  He is married to his wife of 25 years, Luann who is an executive account for a home school education.

The USBTA is built by and for the Bomb Technician Community. Website design by Envie Media. Privacy Policy 

P.O. Box 3189, Centennial CO, 80161, USA. Refund Policy.

Powered by Wild Apricot Membership Software