Kwasnoski’s Corner

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John Kwasnoski


This page is for law enforcement officers and prosecutors who work on crash reconstruction cases.

Get valuable information and quick tips from national expert John Kwasnoski. Learn what works when investigating a crash and presenting the case in the courtroom.


John Kwasnoski has written several articles for the Green Light News, the newsletter for Michigan's Traffic Safety Resource Prosecutor (TSRP) at the Prosecuting Attorneys Association of Michigan. The articles are divided between law enforcement and prosecutor topics.

Click on the image at right to go to the articles.

(Thanks to Ken Stecker, Michigan's TSRP for permission to post these.)

Professor Kwasnoski's Quick Tips

Professor Kwasnoski is has teamed with The Traffic Safety Guy to share tips for prosecutors and law enforcement officers for an effective crash investigation and prosecution.

Click on the image at the left to go to the tips.

Select Books and Publications

Recently, Prof. Kwasnoski authored Kwasnoski’s Little Red Book.  Other publications include: From Crash to Courtroom, Collision Reconstruction for Lawyers and Law Enforcement and Crash Reconstruction Basics for Prosecutors for the American Prosecutors Research Institute. (Now part of the National District Attorneys Association.)

Click on the image at the right to check out these and some of his other publications.

About John Kwasnoski

John B. Kwasnoski is Professor Emeritus of Forensic Physics at Western New England University, Springfield, MA, after thirty-one years on the faculty. He is a certified police trainer in more than twenty states, and has instructed prosecutors, police, and civil attorneys on more than 250 occasions across the U.S. He is the crash reconstructionist on the “Lethal Weapon - DWI Homicide” team formed by the National Traffic Law Center to teach prosecutors how to utilize expert witness testimony and cross examine adverse expert witnesses.

Prof. Kwasnoski has reconstructed more than 1,200 crashes, including multiple and single vehicle, pedestrian, motorcycle, and train crashes, and has given sworn testimony on more than 200 occasions; he has been training the NYPD collision reconstruction unit since 2001; and continues to serve as a consultant to prosecutors nationwide on MV homicide cases. He has worked for more than twenty major insurers as a consultant/expert witness, and has conducted training for claims adjusters and special investigators for a number of insurance companies.

Prof. Kwasnoski is the author and co-author of several books, has published more than 60 journal and newsletter articles on collision reconstruction, and maintains an active speaking schedule nationwide.

Legal Sciences

Legal Sciences , John Kwasnoski's website, is dedicated to providing information, educational resources and training opportunities for professionals involved in the criminal justice system who handle impaired driver and motor vehicle crash cases.

Select Books and Publications

Select publications Professor Kwasnoski authored include: Kwasnoski’s Little Red Book, From Crash to Courtroom: Collision Reconstruction for Lawyers and Law Enforcement and Crash Reconstruction Basics for Prosecutors written for the American Prosecutors Research Institute. (Now part of the National District Attorneys Association.) For more information, visit Legal Sciences 

Kwasnoski's Little Red Book

A readable foundation text for those who want a primer on collision reconstruction. This book is a perfect read for prosecutors and officers who want to gain a new perspective on the science of collision reconstruction.

From Crash to Courtroom

From Crash to Courtroom teaches attorneys what to look for when examining an accident reconstruction expert’s report, and explains in detail numerous potential errors an attorney may encounter. Of equal importance to law enforcement professionals, Kwasnoski’s work also addresses such critical issues as proper evidence collection and effective crash analysis using the correct application of mathematical equations.

Crash Reconstruction Basics for Prosecutors

This publication serves as a primer for prosecutors on the basic science, investigative techniques and questions to ask. Thanks to Professor John Kwasnoski, author and nationally-recognized expert on crash reconstruction, much of the mystery, myth and mathematical phobias surrounding this material are dispelled.