The Australian Federal Police (AFP) has rejected a claim by a senior Canberra barrister that a steep drop in the criminal conviction rate is partially due to shoddy police work and a "cowboy" culture among some officers.
The guilty rate in the ACT Magistrates Court collapsed in recent years, the latest Productivity Commission data shows.
In the five years before 2019-20, 95 per cent of defendants pleaded guilty or were found guilty.
That sank to 65 per cent and 66 per cent in the following two years.
The ACT Bar Association said one factor was what it called an AFP culture of collecting evidence in improper ways.
But police leaders and the AFP union have dismissed these claims as baseless and argued the data used to determine the conviction rate could not be compared to previous years as it included a number of traffic infringements that were dismissed due to a glitch with ACT government speed cameras.
'A bit of a cowboy mentality'
ACT Bar Association vice-president Jack Pappas said some officers regularly used "dodgy behaviour" to obtain evidence, forcing cases to be thrown out of court.
"There are few police who really have a good working knowledge of the Evidence Act … I just don't think they take the time to trouble themselves over it — there's a bit of a cowboy mentality.
"I've seen some appalling instances of police misbehaviour, but I've yet to see a case where there's the slightest hint that the police will be hauled over the coals or taught to do things differently in circumstances where they've effectively mucked up or ruined a prosecution because of their behaviour."
Mr Pappas said the drop in the conviction rate was also explained by the high-quality work of Canberra's legal aid lawyers, as well as police officers overcharging defendants.
"When people are overcharged and they're facing a maximum penalty — let's take, for example, 10 years instead of two years — then the incentive to defend the matter is significantly increased," he said.
Police leaders and union dismiss criticism
ACT Chief Police Officer Neil Gaughan dismissed the bar's commentary, saying there was "no evidence of a systemic issue in ACT Policing or the AFP".
He also said the data used to determine the conviction rate should not be compared to previous years.
"There is a footnote in that table, which is specific in relation to the ACT, about caution being used to compare data over time, due to the fact that an increased number of traffic offences were dismissed with no evidence to offer," he said.
Deputy Commissioner Gaughan said if the alleged actions of police were "endemic" the issue would have been brought to his attention, by the courts or through an ombudsman.
The federal police union's president, Alex Caruana, said Mr Pappas's claims did not stand to reason.
Mr Caruana said that if the bar's accusations of misconduct and poor practice were accurate, the watchdogs that oversaw the AFP would have acted.
"Members of ACT Policing, and AFP more broadly, are subject to the most rigorous oversight of any police force, any politician, any public service in the country," he said.
ACT Director of Public Prosecutions Shane Drumgold said the figures in the Productivity Commission's report did not reflect a ratio between findings of not guilty against guilty and such conclusions reflected a misunderstanding of the data.
"These figures include a range of events, including discontinued backup charges, charges subsequently replaced with more appropriate charges, and traffic infringement notices that were disputed but subsequently paid," he said.
