A veteran traffic police officer who was caught driving 210 kilometres an hour in a 100 zone, on a police motorbike, has pleaded guilty to three charges of excessive speeding while on the job.
Clinton Richardson, 54, was charged with three counts of driving dangerously and at more than 45 kilometres over the limit.
He was found to have travelled at 150 kilometres an hour in an 80 zone on a second occasion and at 180 kilometres an hour in a 60 zone on the third.
Richardson was on the job during each of the offences, conducting roadside traffic checks.
His lawyer, Ray Murphy, told the court Richardson did not speed "for the sake of it", but was attempting to catch up to speeding drivers.
The court heard police were only made aware of the incidents after Richardson pulled over another driver for a roadside drug test.
"The reason this has all come about was the driver in [the third incident] was an antivaxxer [who] took issue with doing the drug test and was arrested," Mr Murphy said.
"He complained to police … they investigated and looked at the body worn camera footage."
Mr Murphy told the court his client was under the "mistaken belief" his speeding was "authorised".
"As far as the police force is concerned, I've had [phone calls from police members] in cases that have this kind of profile … where members have been telling me 'no, no, no, we're allowed to do this'," Mr Murphy said.
The Northern Territory Traffic Act excludes police officers from some dangerous driving offences if the officer is acting in the execution of their duties and if they reasonably believe it's necessary to prevent safety risks.
Prosecutors told the court Richardson's speeding was not reasonable or necessary and posed an unacceptable risk to the public.
The court heard there were no special circumstances to excuse Richardson's actions.
Mr Murphy rejected the prosecutor's suggestions that Richardson was careless behind the wheel, urging Judge John Neil to find he was driving deliberately and "maintaining reactionary gaps" as he sped along Darwin roads.
The court heard Richardson, a senior constable who had spent 13 years with the NT Police traffic operations unit, remains a working police officer but has been issued a caution and transferred to the Joint Emergency Services Communication Centre.
"His transfer to the Joint Emergency Services Communication Centre is somewhat of a transfer to Siberia for a police officer," Judge Neil said.
Judge Neil said Richardson's role as an officer in the traffic operations unit, which saw him attend more than 500 road crashes, should have made him particularly aware of the risks of travelling at such speeds.
"The importance of catching the escaping motorcycle and overtaking on an unbroken white line is to be weighed against travelling at that speed in those circumstances," Judge Neil said.
"It beggars belief it could be regarded as appropriate by a police officer."
Richardson was convicted and fined a total of $4,500 and disqualified from driving for three months.
