This case involves the question of what proofs are sufficient to establish the accuracy of a radar speed-measuring device.
Defendant was convicted in the Sparta Township Municipal Court of operating his motor vehicle at 47 m.p.h. in a 35-mile zone. N.J.S.A. 39:4-98. There followed this appeal, which was heard de novo on the transcript of the proceedings below.
Proof of defendant's speed was the reading obtained from a Mark VI-A radar traffic device. The summons was issued by Sergeant Smith of the Sparta Township Police Department, who was admittedly trained and qualified in the theory, proper operation and calibration of this radar device. Sergeant Smith testified that defendant was travelling southerly on East Shore Road where his vehicle was clocked at the 47 m.p.h. speed.
For 20 years the New Jersey courts have taken judicial notice of the general accuracy of radar speed-measuring devices. State v. Dantonio, 18 N.J. 570, 575-583 (1955). Proof of the accuracy of the particular scientific measuring device used is, however, required as a prerequisite to the admissibility of the results obtained therefrom. State v. Finkle, 128 N.J. Super. 199, 207 (App. Div. 1974),
Sergeant Smith affirmed his knowledge of the three universally accepted methods of testing the accurate operation of radar:
1. By use of the internal tuning fork built into the machine itself. Sergeant Smith testified that activation of the internal tuning fork was not used by him as a method of testing the machine's accuracy, but simply to determine that "the machine is warmed up sufficiently and is operating as per the way it was designed." Indeed, the sole use of the internal tuning fork as evidence of the machine's accuracy would be most suspect. Such testing of the machine by the machine itself has been condemned by the Minnesota Supreme Court as "bootstrapping." State v. Gerdes, 291 Minn. 353, 191 N.W. 2d 428, 431 (Sup. Ct. 1971).
2. By running a patrol car, with a calibrated speedometer, through the "zone of influence" of the radar machine. This was not done in this case.
3. By the use of external tuning forks calibrated at set speeds and which emit sound waves or frequencies identical to those which would come from a vehicle travelling through the radar at the same speed for which the tuning fork has been cut. This was the sole method employed in this case to test the radar set's accuracy.
Defendant was issued his summons for speeding at approximately 1:45 P.M. Sergeant Smith testified that he tested the radar machine three times at the same location: twice shortly before issuing defendant a summons, at 12:35 P.M. and at 1:35 P.M.; and once just after he apprehended defendant, at 2:04 P.M. On each of these three occasions four tuning forks were used to test the radar unit. These forks were calibrated at ...