What is the test for a plea of justification in the use of force?

The onus on a plea of justification in the use of force lies on the party who asserts it: Chartier at para. 64. To bring themselves within the justification contemplated by s. 25, the defendants must prove on a balance of probabilities that: • Cst. Pehlivanian was required or authorized by law to do something in the administration or enforcement of the law; • He acted on reasonable grounds in doing that which he was required or authorized to do; and • In doing that which he was required or authorized to do, he used only as much force as was necessary for that purpose: see Wilsdon v. Durham (Regional Municipality) Police, 2011 ONSC 3419 at paras. 68-69.