Are Police Superior to Non-Police at Recognising Reliable Evidence? Are they More likely to Use Alternative Evidence?

There are three main aims underlying a criminal investigation [2]. Monckton-Smith et al. [2] claim this involves, “to ascertain if an offence has been committed....to identify who committed the crime.... to gather admissible evidence” (p.2). Obtaining evidence that is admissible in court is the task of the police and with this comes a degree of discretion exercised throughout their criminal investigation: reporting and recording crime; decreeing caution; investigating crime; collating evidence; and deciding whether or not to arrest a suspect. Once police have recorded an event as a crime and have identified a suspect, they can then decide on an appropriate deployment option. According to Williams [3] and Williams [4] these options involve decisions of arrest or summons, charge, bail and legal support including advice and caution. Police power operates within the boundaries of written law and the Police and Criminal Evidence Act (PACE) of 1984. The PACE document ensures that police are governed by rules and procedures predicating their investigation process [5]. Stipulations of legal procedure encapsulated in PACE are there to protect potentially innocent suspects such that police are accountable for their actions during investigation. If their actions fall outside of police procedure then an inquiry is held to establish why this occurred and the consequences for all parties concerned are evaluated and dealt with accordingly. Even with rules and procedures in place, police exercise discretion in determining who is judged to be an offender and put on trial in a courtroom [6].