What is the law on the tort of malicious prosecution?

The leading case on the law concerning the tort of malicious prosecution is to be found in Nelles v. Ontario (1989), 1989 CanLII 77 (SCC), 60 D.L.R. (4th) 609 (S.C.C.). Writing for the majority, Lamer J., as he then was, had this to say about malicious prosecution at p. 639: There are four necessary elements which must be proved for a plaintiff to succeed in an action for malicious prosecution: (a) the proceedings must have been initiated by the defendant; (b) the proceedings must have terminated in favour of the plaintiff; (c) the absence of reasonable and probable cause; (d) malice, or a primary purpose other than that of carrying the law into effect.