Former Perth cops Nathan Trenberth, Julian Donohoe avoid jail over ‘violent’ and ‘gruesome’ Fremantle arrest

Two police officers involved in an arrest described by a magistrate as “violent” and “gruesome” have avoided jail.

The 2017 incident was the subject of a Corruption and Crime Commission report which made findings of misconduct against both officers.

The arrest, captured on CCTV, took place in the High Street mall in Fremantle.

The incident played out over less than a minute but it was enough to end the careers of two of the officers involved, former sergeant Nathan Trenberth, a 22-year veteran of the WA police force, and constable Julian Donohoe.

Mr Trenberth admitted to punching a drunk man in the head seven times while trying to arrest him.

The first three blows were deemed acceptable in the circumstances but the court heard the final four were excessive and he was charged with common assault.

Mr Trenberth says it was a volatile situation and he only lashed out after he was kicked five times.

“There was no injury alleged, there was no injury to the male, they were distractionary techniques of little force...” he said.

Mr Donohoe admitted to a charge of assault occasioning bodily harm after he dislocated one of the man's fingers by bending it backwards.

The state argued he "deliberately, vindictively and maliciously" wrenched the man's finger to "cause him pain" and argued he should be sent to jail.

While his defence agreed what he did was wrong they said he had "job fatigue" and he did what he did "out of frustration" and is "deeply ashamed and appalled by what he did."

In sentencing the magistrate said the men were "in a position of power and authority" and the victim was in a "vulnerable position."

He gave Mr Trenberth a fine of $1800 and Mr Donohoe one for $3500.

Both men resigned have from the force.