In Ontario (Attorney-General) v Clark 2021 SCC 18 (30 April 2021) the Supreme Court of Canada explained why Crown prosecutors should have immunity from prosecution by their clients the police for alleged failure to carry out their public duty in the conduct of prosecutions.
The issue of immunity here arose from police complaints that prosecutors had failed to challenge at trial allegations by the defence that officers had assaulted defendants. The result of the prosecutions on charges relating to robbery had been a pre-trial stay of proceedings for one defendant and a reduced sentence for the other who had proceeded to trial.
Prosecutors are not shielded from all claims alleging abuse of powers. There is in Canadian jurisprudence an “accused-centred policy thread woven through the authorities” (majority judgment delivered by Abella J, at [40]). Sometimes, defendants may sue prosecutors, so should police also be able to? No: “allowing police officers to initiate such causes of action would raise profound risks to the rights of the accused and to prosecutorial independence and objectivity, and it would undermine the integrity of the criminal justice system.”
Reasons are: the difference in function of police and prosecutors ([41]), the need for Crown prosecutors to act independently ([43]) being a buffer between the citizen and the police ([44]), the need to avoid injustices and wrongful convictions ([48]), the need to avoid placing prosecutors under pressures which could distort independent decision-making ([51], [53]),the need to protect public confidence in the independent and objective ability of prosecutors to conduct fair trials ([56]), the need to protect defendants’ fair trial rights by freeing prosecutors from accountability to the police whose interests are adverse to those of defendants ([58]).
In summary ([51]):
“Piercing the immunity of Crown prosecutors to make them accountable to police officers puts them in perpetual potential conflict with their transcendent public duties of objectivity, independence and integrity in pursuit of ensuring a fair trial for the accused and maintaining public confidence in the administration of justice.”
Côté J dissented, on the basis that a high threshold for liability for misfeasance in public office would protect prosecutors while also giving remedies for police officers who are subject to severe criticism in criminal proceedings to which they are not parties. The need for a remedy in an individual case should not be obliterated by generalities. For some of the important points made by Côté J, see [117]-[122], [129], [133], [138].