In re the Admissibility of Motor Vehicle Speed Readings

714 A.2d 370, 314 N.J. Super. 211, 1996 N.J. Super. LEXIS 533
CourtNew Jersey Superior Court Appellate Division
DecidedJune 13, 1996
StatusPublished
Cited by2 cases

This text of 714 A.2d 370 (In re the Admissibility of Motor Vehicle Speed Readings) is published on Counsel Stack Legal Research, covering New Jersey Superior Court Appellate Division primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
In re the Admissibility of Motor Vehicle Speed Readings, 714 A.2d 370, 314 N.J. Super. 211, 1996 N.J. Super. LEXIS 533 (N.J. Ct. App. 1996).

Opinion

STANTON, A.J.S.C.

This proceeding involves the reliability of a device known as the LTI Marksman 20-20 Laser Speed Detection System manufactured by Laser Technology, Inc. For ease of expression, I shall hereafter usually refer to this device as the “laser speed detector” or the “detector”. The New Jersey State Police have recently purchased 23 of the detectors and have begun to deploy them in their motor vehicle law enforcement operations. More particularly, a number of the detectors have been used along Interstate Route 80 in the Township of Rockaway and in the Township of Parsippany-Troy Hills in Morris County and numerous speeding tickets have been issued based upon readings produced by the detectors.

Because the laser speed detector has only recently been put into use in New Jersey, its reliability in establishing the speed of a motor vehicle has not been adjudicated in any New Jersey court. A number of defendants in speeding violation cases pending in the Municipal Court of Rockaway Township and in the Municipal Court of Parsippany-Troy Hills Township have filed motions challenging the admissibility of speed readings produced by the [213]*213detector. Approximately 30 pending municipal court cases are affected by those motions. In an effort to avoid numerous separate evidentiary hearings in the municipal courts and in an effort to obtain a comprehensive ruling that would bind a large number of municipal courts, various defense attorneys and Michael M. Rubbinaccio, who is the municipal prosecutor for both Rockaway Township and Parsippany-Troy Hills Township, have requested the Law Division of the Superior Court for Morris County to conduct a comprehensive evidentiary hearing including all of the evidentiary motions presently pending in the two municipal courts. I agreed to conduct such an evidentiary hearing in the Superior Court. Because of the potentially widespread implications of any ruling which might be made, the Attorney General of New Jersey was invited to participate in the hearing. The Attorney General decided not to participate formally in the hearing, apparently because she was satisfied that Mr. Rubbinaccio would adequately represent the interest of the State in the proceeding, but her office has given significant informal assistance to Mr. Rubbinaccio, as have the State Police. I conducted an extensive evidentiary hearing on five court days from May 20 to June 4,1996. On June 5, with the consent of all counsel, I went with State Police Sergeant Robert Ricker to a site on Interstate Route 287 south of Morristown and observed him while he operated the laser speed detector. I also spent some time operating the detector myself.

The laser speed detector is a compact, hand-held device which is covered by United States Patent Number 5,359,404. The patent gives the following summary of the invention embodied in the laser speed detector:

The invention comprises a laser speed detector comprising a laser rangefinder, a sighting scope for a user to visually select a target with an operably-disposed trigger for triggering operation of the detector upon the selected target, and a microprocessor-based microcontroller which is eontrollingly and communicatively interconnected to the laser rangefinder. In a highly preferred embodiment, the instrument is small enough to be easily hand-held.
The laser rangefinder, under the supervision of the controller, fires a series of laser pulses at a selected remote target at known time intervals, and detects reflected laser light from each pulse. Preferably, the pulses are fired at equally-spaced intervals. The laser rangefinder further determines count data reflective of the [214]*214time-of-flight of each pulse to the target and back, and provides these data to the control means. These count data comprise the respective arrival times of a REF (reference) pulse representing the firing time of the laser pulse, and an RX pulse representing reflected laser pulse light.
The microcontroller is configured to read these count values and to compute from them, the time-of-flight of the laser pulse and in turn, the distance to the target. The controller then computes the velocity of the target relative to the speed detector from the change in distance to the target divided by the known elapsed time between firing of the pulses.
The laser rangefinder has several notable features which provide significant improvement in accuracy and reliability (not necessarily listed in order of importance). First, a crystal clock-based timing analysis circuit including a gating circuit which is a digital logic, edge-sensitive gate for which both the “opening” and the “closing” of the time window can be selectably set by the microcontroller. In a preferred embodiment, the microcontroller is configured to alternately widen and narrow the window to selectively lock on “true” RX pulses and exclude pulses due to noise or other factors.
Second, the timing analysis circuitry is constructed to generate self-calibration pulses and to process them in the same manner as the REF and RX pulses, thereby producing a set of calibration interpolation counts. The controller uses these calibration interpolation counts along with the REF and RX interpolation counts to compute self-calibrated values of the respective fractional portions of the clock periods at which the REF and RX pulses arrived. The self-calibration pulses comprise a pair of pulses, referred to for simplicity as TMIN and TMAX, which differ by a known integral number of clock periods (with neither TMIN nor TMAX being zero). Together, TMAX and TMAX define an expanded interpolation interval -within which the fractional portions of the RX and REF arrival times are interpolated. This self-calibrating interpolation provides greatly enhanced resolution and accuracy of distance measurements based on elapsed time.
Third, the laser rangefinder has a first collimator which directs a major portion of an outgoing laser pulse toward the selected target, and a second collimator which redirects a minor portion of the laser pulse to produce a timing reference signal. In one embodiment, the minor portion of the laser pulse is sent to a second light detector separate from a first light detector (here embodied as a silicon avalanche photodiode detector or “APD”) which focusses and receives reflected laser light. Alternatively, the minor portion of the laser pulse is sent to the same detector which detects the returned laser light.

Dr. Daniel Y. Gezari, an astro-physicist who has been employed at the National Aeronautics and Space Administration Space Flight Center for the past 18 years, testified with respect to the general scientific concepts involved in the use of lasers to measure distance and, derivatively, speed. Lasers have been used as a standard tool for the measurement of distances by astro-physicists and other space scientists for a number of years. Mr. Jeremy [215]*215Dunne, a vice president of Laser Technology, Inc. and the designer and inventor of the laser speed detector in question, testified extensively about the scientific concepts involved and about the design and practical operation of the detector. New Jersey State Police Sergeant Robert Ricker, testified about the training of State Police officers in the use of the laser speed detector and about the experience which he and other officers have had with the detector in the field. Mr.

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Bluebook (online)
714 A.2d 370, 314 N.J. Super. 211, 1996 N.J. Super. LEXIS 533, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-the-admissibility-of-motor-vehicle-speed-readings-njsuperctappdiv-1996.