Can a Prosecutor Be Sued For Withholding Evidence From a Defendant?
A Prosecutor That Intentionally Fails to Provide Information or Evidence That Would Be Beneficial to a Defendant May Be Sued For the Tort of Failing to Disclose. A Prosecutor May Be Sued For Failing to Disclose Information or Evidence That Was In Possession or That Was Reasonably Obtainable.
Understanding the Tort of Failure to Disclose Including the Threshold Required to Defeat Prosecutorial Immunity
When a person is accused of by an arm of the government, for concerns ranging from a bylaw breach to a provincial offence to a federal criminal code violation, and more, the prosecutor handling the case against the accused person is immune from liability for negligent handling of the prosecutorial duties; however, a prosecutor may be sued for intentionally withholding of evidence.
The law of failure to disclose, while closely related to malicious prosecution, is viewed distinctively and involves different elements that must be proven and thus a different legal test from that of malicious prosecution. The elements requiring proof in a failure to disclose case were clearly stated in the case of Dunkley v. York Regional Police Services Board, et al, 2019 ONSC 159 where it was said:
 The test for wrongful non-disclosure was recently stated in Henry v. British Columbia (Attorney General), 2015 SCC 24 (CanLII),  2 SCR 214. In articulating the test, the court identified two major policy concerns to which wrongful non-disclosure actions give rise: 1) the possibility of Crown counsel being diverted from their important public duties by having to defend against a litany of civil claims, and 2) the possibility of a "chilling effect" on the behaviour of prosecutors. The court observed that “while the obligation to disclose is non-discretionary, there are invariably difficult judgment calls to be made,” and that “[t]hose difficult decisions should be motivated by legal principle, not the fear of incurring civil liability”. Accordingly, the Court rejected negligence and even gross negligent standards as too lax, and warned that “damages claim for prosecutorial misconduct should not be a mere exercise in artful pleading” at paras. 71, 80, 92-94.
 Ultimately, the court held that for a wrongful non-disclosure claim to succeed at trial, a plaintiff will have to show that 1) the prosecutor intentionally withheld information, 2) the prosecutor knew or ought reasonably to have known that the information was material to the defence and that the failure to disclose would likely impinge on his or her ability to make full answer and defence, 3) withholding the information violated his or her Charter rights, and 4) he or she suffered harm as a result; at para. 85.
 The court went on to note that to demonstrate that the Crown intentionally withheld information, “a claimant need only prove that prosecutors were actually in possession of the information and failed to disclose it” or that “[a]lternatively, a claimant could show that prosecutors were put on notice of the existence of the information and failed to obtain possession of it, in contravention of their disclosure obligations” at para. 86.
As stated in Dunkley, while following the Supreme Court decision of Henry v. British Columbia (Attorney General),  2 SCR 214, a prosecutor may become subjected to liability for intentionally failing to provide information or evidence to a defendant. This liability may arise from failure to disclose information or evidence possessed by the prosecutor or that was reasonably accessible to the prosecutor. Interestingly, the risk of civil liability for failing to obtain and disclose information or evidence may at first appear to impose a broad investigatory requirement upon a prosecutor; however, the requirement is, generally, limited to a reasonable effort to obtain information and evidence that is brought to the attention of a prosecutor. In other words, a prosecutor is without a requirement to conduct a sweeping investigation such as inquiries to any and all government agencies; however, when a prosecutor becomes aware that information beneficial to a defendant may be held by other government agencies, or even potential witnesses. Essentially, a prosecutor must avoid acting with willful blindness to information and evidence that may benefit a defendant. In the Henry case, the Supreme Court specifically stated:
 Nothing in the formulation of this test alters the methods by which finders of fact assess intent. The common sense inference that individuals intend the natural and probable consequences of their actions applies: R. v. Walle, 2012 SCC 41,  2 S.C.R. 438, at paras. 58-63, citing R. v. Daley, 2007 SCC 53,  3 S.C.R. 523. As a result, the evidentiary burden on the claimant is not a high one. To demonstrate that the Crown intentionally withheld information, a claimant need only prove that prosecutors were actually in possession of the information and failed to disclose it. Alternatively, a claimant could show that prosecutors were put on notice of the existence of the information and failed to obtain possession of it, in contravention of their disclosure obligations: see R. v. McNeil, 2009 SCC 3,  1 S.C.R. 66, at para. 49. In both of these circumstances, the intention to withhold may be inferred. This inference is available to the finder of fact, but is not mandatory. Furthermore, it is always open to the Crown to lead rebuttal evidence to show that the withholding was not intentional.
The duty imposed upon prosecutors that requires reasonable steps to obtain information or evidence that may be helpful to the defence of an accused person arises from a duty of loyalty to the administration of justice and foremost duty to pursue truth over and above the effort or desire to achieve successful prosecutions was very clearly stated by the Supreme Court within the case of R. v. McNeil,  1 S.C.R. 66 where it was said:
 The Crown is not an ordinary litigant. As a minister of justice, the Crown’s undivided loyalty is to the proper administration of justice. As such, Crown counsel who is put on notice of the existence of relevant information cannot simply disregard the matter. Unless the notice appears unfounded, Crown counsel will not be able to fully assess the merits of the case and fulfill its duty as an officer of the court without inquiring further and obtaining the information if it is reasonably feasible to do so. Ryan J.A. in R. v. Arsenault (1994), 1994 CanLII 5244 (NB CA), 153 N.B.R. (2d) 81 (C.A.), aptly described the Crown’s obligation to make reasonable inquiries of other Crown agencies or departments. He stated as follows:
When disclosure is demanded or requested, Crown counsel have a duty to make reasonable inquiries of other Crown agencies or departments that could reasonably be considered to be in possession of evidence. Counsel cannot be excused for any failure to make reasonable inquiries when to the knowledge of the prosecutor or the police there has been another Crown agency involved in the investigation. Relevancy cannot be left to be determined by the uninitiated. If Crown counsel is denied access to another agency’s file, then this should be disclosed to the defence so that the defence may pursue whatever course is deemed to be in the best interests of the accused. This also applies to cases where the accused or defendant, as the case may be, is unrepresented . . . . [para. 15]
 The same duty to inquire applies when the Crown is informed of potentially relevant evidence pertaining to the credibility or reliability of the witnesses in a case. As the amicus curiae rightly states, “[t]he Crown and the defence are not adverse in interest in discovering the existence of an unreliable or unethical police officer” (factum, at para. 62). Doherty J.A. made the point forcefully in R. v. Ahluwalia (2000), 2000 CanLII 17011 (ON CA), 138 O.A.C. 154, commenting on the Crown’s failure to inquire further when confronted with the perjury of its own witness as follows (at paras. 71-72):
For reasons not shared with this court, the Crown does not appear to have regarded itself as under any obligation to get to the bottom of this matter. . . .
The Crown has obligations to the administration of justice that do not burden other litigants. Faced with its own witness’s perjury and the fact that the perjured evidence coincided with the incomplete disclosure that the Crown says it innocently passed to the defence, the Crown was obliged to take all reasonable steps to find out what had happened and to share the results of those inquiries with the defence. In my view, the Crown did not fulfill its obligations to the administration of justice by acknowledging the incomplete disclosure discovered by the defence, and after making limited inquiries, professing neither a responsibility for the incomplete disclosure nor an ability to provide any explanation for it. The Crown owed both the appellant and the court a fuller explanation than it chose to provide.
A prosecutor may be held civilly liable for failing to provide proper disclosure to an accused person. For civil liability to apply, it must be shown that the prosecutor was in possession of information or evidence that would favour the accused person and such information or evidence was intentionally withheld resulting in harm to the accused person. Furthermore, even where the prosecutor is without possession, a prosecutor may be found liable for failing to take reasonable steps to obtain information or evidence.