More than one-third of charges under laws that impose mandatory jail terms for serious assaults against public officers have been downgraded, prompting the WA Police Union to claim that "backroom deals" are letting offenders avoid compulsory prison sentences.
But the Criminal Lawyers' Association of WA has rejected claims of a "lawyers' loophole", saying the number of charges being downgraded reflects the proper application of prosecuting guidelines which require the public interest and prospects of conviction to be considered in each case.
Consultant State prosecutor Brent Meertens, of the police prosecuting division, has also defended the system, saying the guidelines, described by former attorney-general Christian Porter as a "safety guard", were being followed.
Mr Meertens said the guidelines ensured that minor offences which resulted in trivial injuries did not lead to compulsory jail terms.
Statistics released by the Government reveal 108 charges have been laid under the laws since they came into effect in September 2009.
Jail terms have been imposed in 33, or 38 per cent, of the 87 cases finalised by the courts.
In another 36 per cent of cases, or 32 charges, the trigger which attracts the mandatory jail sentence was removed and the charge downgraded, resulting in a non-custodial penalty.
In 18 cases the charges were dismissed, four were withdrawn and 21 cases are still before the courts.
The statistics also show there was a 28 per cent drop in reported assaults against police in the first year the laws were operating, from 1346 between September 2008 and August 2009 to 974 in the same period the following year.
There was another 12 per cent drop, to 850 reported assaults against police, in the second year and then a 5 per cent increase to 892 reported assaults in the third year.
Police Union president George Tilbury said the situation was unacceptable and immediate action was needed to keep "thugs who assault police officers off the street".
"Criminals are now learning that if you assault an officer, a lawyers' loophole can give you a get-out-of-jail-free card if you plead guilty to a lesser charge," he said.
Criminal Lawyers' Association president Linda Black said it was inevitable that the mandatory jail term was considered when prosecuting authorities decided whether it was in the public interest to pursue a charge.
Police Minister Liza Harvey said the statistics showed an encouraging decrease in reported assaults on police since the laws came into effect and the application of the legislation had been closely monitored to ensure it was being used appropriately.