Which of the following actions is permissible for private investigators under Ontario law?

The permissible action for private investigators under Ontario law is the use of legal tools to compile evidence. Private investigators operate within a framework that mandates adherence to legal standards and regulations when collecting evidence. Utilizing legal tools ensures that the evidence gathered is both admissible in court and collected in accordance with privacy and other applicable laws.

This option aligns with the professional responsibilities of private investigators, who are expected to conduct their work with integrity and legality while respecting the rights of individuals. Legal tools can include databases, public records, interviews, and other methods that do not infringe upon privacy rights or require illicit activities.

In contrast, conducting investigations without a license is against the law in Ontario, as private investigators must be registered and be in compliance with the Private Security and Investigative Services Act. Using electronic surveillance in private properties without consent infringes upon privacy rights and is generally illegal without proper authorization. Assisting police in arresting suspects falls outside the typical scope of a private investigator's duties and may require special arrangements or a different legal context to be permissible. Thus, the use of legal tools to compile evidence stands out as the correct choice that respects the boundaries of legal practice for private investigators in Ontario.