Shaun Malone was 17 when a Petaluma police officer pulled him over on Lakeville Highway the morning of July 4, 2007, and wrote him a ticket for going 62 mph in a 45-mph zone.
Malone, now 19, was ordered to pay a $190 fine, but his parents appealed the decision, saying data from a GPS system they installed in his car to monitor his driving proved he was not speeding.
What ensued was the longest court battle over a speeding ticket in county history. The case also represented the first time anyone locally has tried to beat a ticket using GPS.
Nationally, such cases remain rare, despite the growing use of such technology in vehicles, primarily for mapping purposes.
In her five-page ruling, Commissioner Carla Bonilla noted the accuracy of the GPS system was not challenged by either side in the dispute, but rather they had different interpretations of the data.
All GPS systems in vehicles calculate speed and location, but the tracking device Malone's parents installed in his Toyota Celica downloaded the information to their computer. The system sent out a data signal every 30 seconds that reported the car's speed, location and direction. If Malone ever hit 70 mph, his parents received an e-mail alert.
Malone was on his way to Infineon Raceway when Officer Steve Johnson said he clocked Malone's car going 62 mph about 400 feet west of South McDowell Boulevard.
The teen's GPS, however, pegged the car at 45 mph in virtually the same location.
At issue was the distance from the stoplight at Freitas Road -- site of the first GPS "ping" that showed Malone stopped -- to the second ping 30 seconds later, when he was going 45 mph.
Bonilla said the distance between those two points was 1,980 feet, and the GPS data confirmed the prosecution's contention that Malone had to have exceeded the speed limit.