Actually they can be, they shouldn't be, but they can be.
I just think that more is needed. I checked out some websites:
[SIZE=+1]"Investigation and Laying a Charge[/SIZE]
When a crime is reported to the police, they do an investigation to determine if there is enough evidence to be able to charge any person with the offence.
Once a criminal charge is laid at the court by the police, the person who is accused of the crime is referred to as the accused or the defendant. The person who reported the crime is referred to as the complainant. Sometimes the complainant is not the same as the victim who suffered injury or harm as a result of the crime.
Although individual citizens have the right to lay a criminal charge, this is unusual as s/he would be personally responsible to collect evidence and to present this private prosecution case in court.
[SIZE=+1]Will the Accused be Arrested?[/SIZE]
The police may arrest the accused at the time of the incident or when they inform him/her of the criminal charge, or they may give him/her a summons which is an order to appear in court at a certain time to answer the charge.
Usually the accused person will be released from custody within 24 hours after arrest unless there is sufficient evidence for a judge to determine that releasing him/her would threaten the safety of the victim or others or there is reason to believe that s/he will not turn up for the trial.
Sometimes the accused will be released on an undertaking or recognizance with conditions such as to stay in a particular area, have no contact with the victim or others, or not to use alcohol or firearms. If the accused breaks any of the conditions, s/he can be charged with a breach and may be taken into custody. "
http://www.gov.ns.ca/just/PolVS/CJSBrochure.htm#investigation
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In some provinces/territories, the police lay charges, in others, the Crown prosecutor does. In other situations, the police will consult with the Crown prosecutor and the complainant.
Criminal charges are laid when:
- the police have talked to the Complainant/victim
- there is enough evidence to show that a crime was committed
- the police are able to determine who is responsible for the crime
- the police have spoken to the Crown prosecutor
While there are guidelines to follow when deciding to charge a person with a criminal offence, some flexibility or choice still exists. For example, the police may decide not to lay a charge if the victim does not want to pursue the matter.
In crimes such as child abuse and domestic violence, the police have specific guidelines to lay charges.
Where there is enough evidence and a decision is made to charge the person responsible, the person is now an
accused and is taken before the courts."
http://www.courtprep.ca/en/justiceProcess/arrest.asp
I just find it hard to believe that absolutely nothing would be required to lay charges.