Reasons - Probable Cause

Reasons For Probable Cause

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By Perry J Zucker 

Role and Responsibility of the Expert Witness - Engineer

An engineer expert witness (EEW) is someone who specializes in engineering,  that assist the judicial system  (judges and/or juries and/or lawyers) to  understand the technical aspects of their case. They may be asked to explain how science applies to certain situations, in cases of laws and/or regulations. The EEW, may testify about police speed measuring devices / traffic control devices, geographic of the specific roadway as well as the proper use of the said device.


Definitions of Traffic Probable Cause

"A well-grounded suspicion that a crime has been or is being committed”(+). The facts and circumstances must show a "`reasonable ground for belief of guilt.

Most "Probable Cause" traffic stops are for an indirect reason(s). Some of these vehicle traffic stops were initialized by:


Police Laser / Lidar Speed Gun - Expert

Measures speed by utilizes an infrared light beam, which is activated by the Police Officer, at a moving target (your vehicle). The officer observed the target vehicle (yours / defendant) and reads the speed display of the laser/ lidar unit.


Police Radar Gun / Unit  - Expert

Measures speed by utilizes RF, which is activated by the police officer, at a moving target (your vehicle). The officer observed the target vehicle (yours / defendant) and reads the speed display of the radar unit.


Police Pacing / Pace / Clocking Expert

Measures speed of the target vehicle (yours) by keeping a uniform distance from the rear / front / side for a specific distance(s) and reads the speed of his/her speedometer.


Police Gap Time / Timing / Robic / Vascar / ENRADD Expert

Measures speed of the target vehicle (yours), utilize a method that uses a timing theory between two (2) points with a known distance.


Disobey Traffic Control Device (Traffic Ticket) - Expert

The police officer observes a target vehicle passes a traffic signal, sign, and/or crossing a pavement marking(s), etc. Faulty Equipment (ticket) - The police officer observes a target vehicle that has standard equipment not operating, e.g. headlight(s), taillights, etc. and/or equipment that should not be operating. DUI / DWI ( Driving Under The influence) / (Driving While Intoxicated) - The police officer / trooper observes the target vehicle is driving erratic, such as weaving, swerving, various speed(s), and/or not driving reasonable and prudent for environmental / roadway condition(s).Traffic Stop - Once, the vehicle (yours) is pulled over to a safe portion of the roadway, the police officer / trooper will make a determination, if any further action(s) should be taken, such as authorized or unauthorized search for marijuana, heroin, cocaine , pills, drugs, etc, person of interest interview(s), traffic speeding ticket(s) and/or arrest, as well as possibly impounding the vehicle in question. (+) In some States


Reasons For Probable Cause - Expert

In order for a law enforcement officer to make a lawful probable cause traffic stop, they must meet certain key elements (See Above). It is these type of cases, that a probable cause traffic stop expert witness will be critical. 


The Offices Of Perry J  Zucker, Degreed Engineers,  are a nationally recognized highly successful and aggressive expert engineering firm, since 1993. Our team of experts (in-house engineers, techs and support staff) handle police speeding / traffic control device(s) tickets / violations, for probable cause traffic stops.  



Our Expert Witness Services - Locations

Includes the following states: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey (NJ), New Mexico, New York / NY / New York City / NYC, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania (PA) , Rhodes Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming.


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