Serious doubts have been raised about the reliability of police laser speed detectors, according to a Perth electrician who had his car impounded for three months for a "hoon offence".
Aaron Fitzgerald was charged with reckless driving after being pulled over by a police officer twice on April 6 last year.
In the Joondalup Magistrate's Court yesterday, Mr Fitzgerald had his charge downgraded to a speeding infringement after traffic expert Bob Davey analysed GPS and computer data from his vehicle and concluded he had been travelling 39km/h slower than police originally alleged.
The first time he was pulled over by the officer, who was on a motorcycle and using a hand-held laser detector, Mr Fitzgerald was told he was driving at 89km/h in a 70km zone on Wanneroo Road.
The 28-year-old, who believed he was in an 80km zone, was issued a speeding ticket which imposed a $150 fine and two demerit points.
The same officer then pulled him over about 4km further along Wanneroo Road, alleging he had recorded Mr Fitzgerald driving at 127km/h in the 70km zone after he had driven 319m from where he was first stopped.
Mr Fitzgerald was charged with reckless driving and the vehicle he had been using, a Holden HSV GTS owned by his father, was impounded under "hoon" laws. Mr Fitzgerald then substituted the impounded car for his own vehicle. The charge was withdrawn yesterday after Mr Davey gave evidence that Mr Fitzgerald had been driving at 88km/h on the second occasion, not the 127km/h as alleged.
Mr Fitzgerald was instead issued another $150 fine and two demerit points. He was awarded costs, but said he remained out of pocket for some legal expenses and should be compensated for the inconvenience of having the car impounded.
"At the end of the day, I have been treated as guilty until proven innocent," Mr Fitzgerald said.
Lawyer Terry Dobson said the courts could no longer totally rely on laser device readings.
"This is not a case of reasonable doubt - we have proved the reading was wrong," Mr Dobson said.
A WA Police spokeswoman said the prosecutor had withdrawn the charge after deciding there could be "some question" about the accuracy of the laser reading in the particular circumstances of the case.