In-Person Training

Calculating Speed from Video Images | Spokane Police Academy

October 28, 2021 8:00 am
October 28, 2021 5:00 pm
Pacific Time (PST)
The Spokane Police Academy, 2302 N Waterworks St, Spokane, WA 99212   View map


Join us for a unique one-day training course for investigators who calculate speed from video evidence. The experts from iNPUT-ACE will be joined by Detective Josh Guthrie and Grant Fredericks, Forensic Video Analyst and FBI National Academy instructor, to discuss calculating speed from video images.

Learn about the latest technological advancements that are enabling officers to calculate speeds with greater accuracy and precise margins of error.

Registration is required but completely free. We look forward to seeing you there!


Event Details

Brought to you by:

Spokane Police Department

iNPUT-ACE video evidence software and training


Course Description

According to a recent industry survey, 85% of police investigations involve video evidence, including crash events. At the same time, few traffic collision analysts have received the proper training to examine this prolific and powerful digital asset. To determine speed, many investigators and accident reconstructionists rely on the discredited and deeply flawed practice of counting frames. This course exposes crash investigators to the frailties of relying on timestamps and certain types of file metadata to determine frame timing and vehicle speed.  Investigators will discover how frame timing is stored in video streams and will explore methods to test and validate actual frame rates. This hands-on program guides participants through video acquisition, image refresh rate analysis, and it unlocks repeatable methods for determining and reporting a reliable margin of error for critical speed analysis casework.

Learning Objectives

  • Crash analysts will examine actual case examples where investigators incorrectly calculated timing from video resulting in erroneous speed/force analyses.
  • Investigators will understand and be able to articulate frailties associated with calculating timing using unreliable methods such as frame counting.
  • Investigators will learn how timing is stored in video files and discover how to identify when timing metadata is unreliable.
  • Investigators will learn how variable image refresh rates can affect the outcome of a speed/force analysis.
  • In hands-on coursework, investigators will practice techniques and methods to test and report reliable frame timing for the purpose of evaluating speed estimation in crash examinations.
  • Investigators will test, experience and understand scientific methods used to validate and articulate the potential rate of error of speed estimation from digital video evidence.  


iNPUT-ACE video evidence software and trainingDet. Josh Guthrie is partner/owner of Force Analysis and Multimedia Review, LLC which provides services related to the examination of police use of force and crash events based on video evidence.  Josh is an active law enforcement officer with 22 years of service.  He is an A.C.T.A.R. accredited collision reconstructionist and specializes in 3D laser scanning and reverse projection photogrammetry, and speed analysis from video images.  Josh has also served as a patrol officer, instructor, and is currently assigned as a critical incident reconstructionist and multimedia specialist for his agency. During his time as an instructor, he has trained thousands of law enforcement officers in collision reconstruction, scene analysis, and police use of force policy and tactics.



iNPUT-ACE video evidence software and trainingGrant Fredericks is a Certified Forensic Video Analyst and contract instructor at the FBI National Academy in Quantico.  Grant specializes in the video examinations of Officer-Involved Shooting incidents. As a consultant for Major Crime and Joint Forces Operations, Grant provides technical consulting for the nation’s most high-profile video-related cases. His work won the International Association of Chiefs of Police top award for Technical Advances in a Criminal Investigation.  He has testified over 300 times in courts throughout the US, Canada, the UK, New Zealand, and in other parts of the world.  He has consulted for the US Department of Justice, the IACP and the National Institute of Justice and is a co-author of Digital Video Systems Minimum Performance Specifications for Digital In-Car Video Recording Systems for US law enforcement.  Grant is a former police officer and coordinator of the Vancouver Police Forensic Video Unit in Canada.



iNPUT-ACE video evidence software and trainingBrandon Wahl is a LEVA Certified Forensic Video Technician and Technical Support Director for the iNPUT-ACE software. As a Forensic Video Technician, Brandon has assisted on hundreds of video-centric investigations and continues to help agencies decode proprietary video file formats, process digital multimedia evidence, and prep demonstratives for court. Brandon has been a member of the iNPUT-ACE team since the launch of the software in 2016 and continues to train investigators on accurately decoding and interpreting video evidence.





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