Police officers may be held liable for substantial damages where the identity of a tipster is revealed in breach of a promise of confidentiality. That's what the Ontario Court of Appeal ruled in its recent decision in Nissen v. Durham Regional Police Services Board1,

In Nissen, the plaintiff had learned that the teenaged son of a neighbour had broken into another neighbour's home, stolen guns and, together with his brother, taken those guns to school and threatened other students. She claimed she provided this information to police only after gaining assurances from the interviewing officer that her anonymity would be protected.

Ultimately, the two teenagers were arrested and charged with respect to the reported incident. As part of the Crown disclosure in the criminal proceeding, the identity of the plaintiff was disclosed along with a videotape of her police interview, the existence of which had been unknown to the plaintiff. Following this disclosure, the plaintiff was subject to threatening and harassing conduct by the boys' parents. Ultimately, she and her family sold their home due to the harassment and moved to another community. The plaintiff was also diagnosed with post-traumatic stress disorder ("PTSD").

At trial, the plaintiff's case was framed as an action for breach of informer privilege by the police. The trial judge accepted that the interviewing officer had assured the plaintiff that her identity would be kept confidential and that the failure to do so amounted to a breach of informer privilege. The trial judge awarded her damages for emotional and psychological injury in the amount of $345,000 and allowed claims for her family members under Ontario's Family Law Act for loss of guidance, care and companionship.

On appeal, the police service argued that the trial judge made an error of fact in finding that the plaintiff had been promised confidentiality by the interviewing officer but that, in any event, the trial judge erred in his consideration of the necessary elements of a claim for damages for breach of informer privilege. The police further argued that the awarded damages were excessive.

The court rejected the argument that the trial judge made an error of fact, concluding that there was no basis to interfere with the finding that the plaintiff had been promised confidentiality as it was grounded in the trial judge's assessment of the plaintiff's credibility and reliability as a witness, which is ultimately entitled to deference on appeal.

With respect to the issue of breach of informer privilege, the police argued that a claim for damages will not lie unless it is established: (i) the information provided must be difficult or impossible to obtain; and (ii) the informer must be likely to suffer harm or danger if her identity is disclosed.

In this case, the police argued that given that the information provided by the plaintiff was readily available and that there was no basis to believe she would be in danger in the event her identity was disclosed. Moreover, the police service asserted that, because the interviewing officer had not followed the Durham Regional Police Criminal Informant and Agent Management Directive, she could not be deemed a confidential informant.

The court rejected these further arguments finding that the case should be resolved as a claim for damages for breach of confidence. As the interviewing officer had promised the plaintiff confidentiality, this gave rise to a common law and equitable right entitling her to have her identity protected. The right was not contingent on other ways that the police may have had to get the information or on the perceived danger she faced. Once the promise was made, she was entitled to rely on it.

With respect to the damages, the Court of Appeal declined to interfere with the quantum ordered by the trial judge. While describing the award "very generous", there was no error of law or principle made warranting intervention.

The decision in Nissen makes clear that police officers retain the discretion to determine whether to offer anonymity to witnesses in order to obtain information from them. However, once the promise of confidentiality is made to an individual, the police will be held to that promise and any subsequent breach may give rise to a claim for damages.

1Nissen v. Durham Regional Police Services Board DATE: 20170109, 2017 ONCA 10 (CanLII)