A "highly aggressive" former police officer who dragged a teenager from a car in a headlock for "being a smartarse" has avoided an assault conviction after telling a court of his remorse.
James Head, 32, was a probationary constable with ACT Policing when he and then-senior constable Matthew McVicar, 37, assaulted the victim during an unlawful arrest on Australia Day in 2017.
The pair were nearing the end of their shift when they stopped a teenager who drove through the Civic bus interchange and took longer to pull over than they would have liked.
Head approached the car and began aggressively interrogating the driver.
Mobile phone footage captured by the front seat passenger shows Head threatening to search a teenager in the back seat for "being a smartarse", before hauling him out onto the ground where he was handcuffed.

Head and McVicar claimed to have arrested this teenager for hindering police, but they had no lawful justification for doing so.
Both were suspended from duty without pay upon being charged and in 2018 Magistrate Robert Cook found the pair guilty of common assault, describing their use of force as "highly excessive".
They have since challenged the verdicts twice in higher courts, without success.
In one of the failed appeals, Justice David Mossop described video of the incident as "disturbing" and called the then-officers "highly aggressive, loud and ill-mannered".
In the other, a panel of three judges commented that Head and McVicar had "simply ignored the rules" and overreacted to the victim being "cheeky".
The pair were ultimately sacked by the AFP and the case returned to the ACT Magistrates Court.
McVicar was sentenced last month to a good behaviour order after Mr Cook found it was not necessary to record a conviction.
And on Monday, Head's lawyer Tim Sharman argued the 32-year-old should be dealt with in the same way.
Mr Sharman conceded Head's conduct on the night in question had "left a lot to be desired", but he said it was out of character for a man who had enjoyed an "exemplary" military career before becoming a police officer.
He said Head had already suffered great consequences, having had to relocate to Queensland to find work after losing his "cherished" job.
Head also briefly addressed the court via video link, saying he was remorseful and he wished he could go back in time to do things differently with the benefit of experience.
He said he had brought the names of himself and his family into disrepute.
But prosecutor Dean Sahu Khan questioned whether Head was really remorseful, saying he had seen no evidence of this.
He said the sentence should send a strong message because police officers were meant to protect people, not assault them.
Mr Cook ultimately accepted there was remorse and that Head's offending had been "an aberration".
"Your actions were impulsive, there was no planning and it was not premeditated," the magistrate said.
In sentencing, Mr Cook said he had considered factors including Head's otherwise good character, the fact the incident had occurred at the end of a long shift and that Head had been the more junior of the now former officers.
But he remarked that Head's conduct was clearly an overreaction and it should not take much experience to know members of the community ought to be approached and treated with respect.
"Was there a reason for the officer to do what he did to the complainant that night? Not at all," Mr Cook said.
"He failed himself, his family, the community and ACT Policing."
Mr Cook found the loss of Head's job and the "repeated ventilation" of the case in the media amounted to extra-curial punishment and a conviction was not necessary.
He imposed the same sentence McVicar received, ordering Head to be of good behaviour for 12 months.