Yesterday, one man died and about ten people were injured after a van veered off the road and drove into worshippers leaving prayers outside the Finsbury Park mosque in London.In the most recent wave of terrorist attacks the perpetrators either took their own lives or were killed and in several cases arrested by the police. This time, the deliberate attack to harm took a different route when a number of brave men at the scene arrested one of the terrorists and handed him to the police.I believe the police cannot fight this ongoing global battle alone. Private citizens must help in this unprecedented age of terrorism.There are rules, though, for citizen arrests. One cannot just detain a man on the street on suspicion of wrongdoing — an unpleasant scene I have seen numerous times during my work in the field as a journalist.In Canada, the law once stated that members of the public “must find a person either in the act of committing a crime, or escaping from and freshly pursued by persons who have lawful authority to arrest that person.”Article Continued BelowThe laws have become more flexible in Canada to allow more citizen arrests.In the past, a citizen could arrest someone only if the perpetrator was found committing the crime. More recent laws allows the arrest “within a reasonable time” of the offence. For example, it would be lawful to chase a shoplifter after he leaves a store and arrest him. The apprehension is only lawful if no police officer is able to capture the thief at the time of the incident.The Canadian Citizen’s Arrest and Self-Defence Act does not clarify the “reasonable time” allowed — an ominous legislation leaving critiques demanding more clarity.