Defence of Property
Defence — property
35. (1) A person is not guilty of an offence if
- (a) they either believe on reasonable grounds that they are in peaceable possession of property or are acting under the authority of, or lawfully assisting, a person whom they believe on reasonable grounds is in peaceable possession of property;
- (b) they believe on reasonable grounds that another person
- (i) is about to enter, is entering or has entered the property without being entitled by law to do so,
- (ii) is about to take the property, is doing so or has just done so, or
- (iii) is about to damage or destroy the property, or make it inoperative, or is doing so;
- (c) the act that constitutes the offence is committed for the purpose of
- (i) preventing the other person from entering the property, or removing that person from the property, or
- (ii) preventing the other person from taking, damaging or destroying the property or from making it inoperative, or retaking the property from that person; and
- (d) the act committed is reasonable in the circumstances.
(2) Subsection (1) does not apply if the person who believes on reasonable grounds that they are, or who is believed on reasonable grounds to be, in peaceable possession of the property does not have a claim of right to it and the other person is entitled to its possession by law.
(3) Subsection (1) does not apply if the other person is doing something that they are required or authorized by law to do in the administration or enforcement of the law, unless the person who commits the act that constitutes the offence believes on reasonable grounds that the other person is acting unlawfully.
R.S., 1985, c. C-46, s. 35; 2012, c. 9, s. 2.
Use of Force
A property owner is permitted to use reasonable force to remove someone who is trespassing.
R v Lauda, 1999 CanLII 970 (ON CA) at para 65 ("persons in peaceable possession of a dwelling-house or real property (which I take to include unoccupied lands) are entitled to use reasonable force to prevent trespassing and to remove trespassers from their property.")
R v Kephart and Oliver (1989), 44 CCC (3d) 97 (ABCA) at para 9
R v Assante-Mensah, 2003 SCC 38 (CanLII),  2 S.C.R. 3
- MacDonald v. Hees,  N.S.J. 356 ("“no greater than could possibly be considered by any reasonable man to be requisite for the purpose of removing" the trespasser)