Forensic Accident Reconstruction Software

"Our goal is to provide software that is Easy To Use and provides at least as much, if not more than, what is suggested or promised in our marketing materials and pricing."

    4N6XPRT Systems® is a dba of Expert Witness Services, Inc., a California corporation. Expert Witness Services, Inc. has been in business since 1974, and 4N6XPRT Systems® since 1990.

    4N6XPRT Systems® has developed, published, and currently offers for sale the following programs: Expert AutoStats®, 4N6XPRT StifCalcs®, 4N6XPRT BioMeknx®,  Expert Qwic Calcs®, Expert VIN DeCoder®, Expert TireStuf®, and 4N6XPRT Ped & Bike Calcs®.

    The original programs were developed by Daniel W. Vomhof, Ph.D.,  and Daniel W. Vomhof III. The program developers are Court Qualified Accident Reconstructionists with over 65 years of combined reconstruction, A.C.T.A.R. Certified Accident Reconstructionists, and Board Certified Forensic Examiners.

    The principal product for which 4N6XPRT Systems is known is the Expert AutoStats® program. Since its introduction in 1991, Expert AutoStats® has grown from a database of 12,000 vehicles to over 43,000 vehicles in the 2013 edition. Unlike printed sources, each update corrects reported omissions in the existing data as well as adding the new models. It is currently the only database program available for purchase having this depth of models, breadth of years, and detail of information. Expert AutoStats® is owned by over 300 Government agencies and 700 private consultants within the United States, Canada, and South America, as well as several major automotive manufacturers and insurance claims departments.

    Customer service/support for registered owners of the current program version includes providing corrected data at no charge when an error in dimensions or an omitted vehicle is called to our attention. This correction is usually e-mailed to the reporting party within 24 hours.


Download Program Order Form as a PDF document

Our current Software Programs:


Program Page

Program Notes

Expert AutoStats logo


AutoStats ®

2014 Update began shipping February 2014

Expert Autostats provides the  dimensional  and performance data important to a vehicle accident investigator and reconstructionist in an EASY to use, yet very complete, program. The database includes information on over 44,000 model year passenger cars, vans, utility vehicles, and pick-up trucks intended for sale in the United States. Sample Printouts from various conferences can be accessed from the Conference Crash Test Summaries Page.


Go to - Screen Shots - to see the new look and feel

4N6XPRT StifCalcs logo


StifCalcs ®

2013 Update began shipping July 2013

4N6XPRT StifCalcs provides Quick, Convenient, Easy   access to the NHTSA Crash Test data on your own MS-Windows computer without the need for an internet connection. Sample Printouts from various conferences can be accessed from the Conference Crash Test Summaries Page.

NOW with Force Balance Calculation Module!!

Expert VIN DeCoder Logo


VIN DeCoder ®

2013 Update began shipping December 2013

Expert VIN DeCoder is User Friendly Software used to provide interpretation of the 17 character VIN Number on Cars, Light Pickups, Utility Vehicles, and Vans. Sample Printouts from various conferences can be accessed from the Conference Crash Test Summaries Page.

4N6XPRT BioMeknx Icon Image


BioMeknx ®

Released 12/28/2007

4N6XPRT   BioMeknx collects the Biomechanical data of importance to the Accident Investigator into one easily accessible reference location

Expert Qwic Calcs logo


QwicCalcs ®

Expert Qwic Calcs provides Fast, non-mathematical   answers to questions of importance in crash evaluations.

non-mathematical= no math background necessary to use the program
and obtain "correct" results

Expert TireStuf logo


TireStuf ®

Expert TireStuf is useful for evaluating many aspects of Passenger Car and Light Truck tire information.

4N6XPRT Ped and Bike Calcs logo


Ped & Bike Calcs ®

4N6XPRT Ped & Bike Calcs is useful for evaluating vehicle speeds in Vehicle vs. Pedestrian/Bicyclist accidents.


Other Services Offered:

Individual Vehicle Data Search Service ® ...... or ...... IVDSS ®

This is, as the name implies, a service where you can order data on individual vehicles. You may order Dimensional Data, VIN information, (and NHTSA Crash data when available) on individual vehicles, including : Autos, Vans, Motorcycles, Semi tractors/Trailers, Trucks and some Construction Equipment

Force Balance Analysis Service added to our IVDSS Vehicle Information Service

A  Force Balance module is now included  in 4N6XPRT StifCalcs® beginning with the 2011 version of the program  -   As an extension of our Individual Vehicle Data Search Service, we have now added Force Balance Analysis runs to the services we offer.   An order form with pricing fcan be downloaded from this link.

Articles, Papers, Publications,  and Manuals

Summaries of Past Conferences with Selected Conference photographs, video, and sample printouts for the Crash Test vehicles from our software

Upcoming conferences

Interesting tidbits

Links to other sites and Resources


® - Denotes a Trademark registered with the USP& TO. All of the program materials are copyrighted under U.S. and International Law.

The programs are licensed to a single registered user . They may be installed on Three (3) single station/single user computers concurrently. Installation on a network computer for corporate/entity wide use at multiple locations is a violation of the licensing. An example of the three installations for a private consultant would be  -

1 at the office/workplace

1 at the home of the registered user

1 on a portable/laptop to be used in the field or in court {by the registered user}

The Registered User may be the owner or an employee of that owner, so long as only one person can access the program at a time.


  Top of Page

4N6XPRT StifCalcs puts the NHTSA Crash Test database on your computer, WITHOUT AN INTERNET CONNECTION. Just access the database to develop A-B-G and Crush Factor stiffness values anytime of the day, any day of the week, as long as your computer is "up and running".

As of its powerful 2013 release, EXPERT AUTOSTATS, one of our most popular programs, provides dimensional data on over 43,000 automobiles, vans, utility vehicles, and pick-up trucks intended for sale in the United States. A limited number of models intended for sale elsewhere are also included.

Count on 4N6XPRT Systems' accident reconstruction software to help you reliably and efficiently evaluate and analyze accident information with some of the easiest, most trusted and most cost-efficient software you can find in the industry today.

ALSO OFFERING: Articles, Papers & Manuals, Past Conference Summaries, Upcoming Conferences, Interesting Tidbits, Additional Resources, Sample Program Output.

"This software is very worthwhile, constantly being improved, and is formidable tool in my and my firms arsenal. I heartily recommend these products, and the cheerful, competent, and friendly assistance that comes with them." - John Howell ACTAR 1543
"On a regular basis we utilize 4N6XPRT's Expert AutoStats, Expert VIN DeCoder and 4N6XPRT StifCalcs programs. It's great having these tools to work with." - James A. 'Jim" Moore JAM/MVA, Inc.