Police powers - under the Crimes Act and Law Enforcement (Police Powers and Responsibilities) Act emphasise the difficulties surrounding police discretionary powers - yet this is balanced somewhat by warrants acting as judicial safeguards against police abusing their powers - eg. warrants for a more 'legally enacted' investigation process, phone taps or surveillance - but also warrants to reinforce police search powers of 'search and seizure' with 'reasonable force' and on 'reasonable grounds.' However, despite the Crime Act enshrining the police having the ability to 'search, seize and detain things', and the police acting as a separate executive arm to the Government, many argue that police still violate and 'step boundaries' - this prejudice of the 'rule of law' is highlighted statistically by police targeting up to 75% of children, telling them to 'move on' as well as the highly disputed shaking of hair, tongue swabs eg. as part of their investigation
The cases set out for investigation themselves also to some extent dispute the efficacy of the criminal trial process - i.e. police only undertake cases they feel sustain sufficient resources and severity/indictment - as can be seen in R v Munster (2009). - However, processes of arrest do support the criminal trial process - as suspects or the accused can only be questioned after they are accused, after which sufficient evidence is gathered and fingerprint/DNA technology in accordance wit the Evidence Act 1995 (NSW) - this effectiveness is upheld by police gathering witness testimonials and physical or 'real' evidence such as posters, charts and as seen in R v Campbell (2010), police, with the assistance of ballistic and sociologic experts, found that the branch had snapped adjacent to the body fallen 50m from Sydney Olympic park. - This idea of 'beyond reasonable doubt' is, conversely, questioned as some DNA evidence