In Canada, a police officer has the power to arrest a person if the police officer has reasonable grounds to believe that the person has committed a criminal offence. The arresting police officer may or may not place handcuffs on the person under arrest.
Suspicious circumstances alone are not reasonable grounds to arrest a person. The officer must have enough facts or evidence available that a reasonable person would believe that the suspect has committed or is about to commit an offence.
A reasonable person placed in the position of the officer must be able to conclude that there were indeed reasonable and probable grounds for the arrest. However, at the same time, the police do not need to show a strong case that would result in a conviction in order to effect an arrest.
A person placed under arrest by the police should not challenge the grounds for the arrest. A person who challenges or resists arrest may face further criminal offences. Whether or not the arrest was lawful should be discussed with an experienced criminal defence lawyer after the fact when mounting a defence. You are very unlikely to talk the police out of arresting you. However, there is a high probability that you will make matters worse.
Not all persons charged with criminal offences are physically arrested by the police. For example, the police may simply serve the accused person with an Appearance Notice. This does not require an arrest or a trip to the police station.
Section 501 of the Criminal Code provides that an Appearance Notice must state: the name of the accused, the criminal charge and the time, date and place where the accused must attend court.
In addition, the Appearance Notice can require the accused to attend a location on a certain date for fingerprinting. The accused must attend on such a date for fingerprinting and failure to do so can result in additional criminal charges.
If the accused does not attend the court appearance, the court can issue a warrant for arrest and the police may then arrest the person and bring them to court in custody.
If you have been arrested, or if you have received an Appearance Notice, you should immediately take steps to retain an experienced criminal defence lawyer. The propriety of your arrest is one of the areas the lawyer will explore in advancing your defence to the criminal charges against you.