The defence of alibi (Latin for “elsewhere”) arises where there is an air of reality that, at the time of the commission of the offence, the accused was not present at the scene of the crime.
The requirements of an alibi are strict; evidence that an accused had only a limited opportunity to commit a crime is not an alibi.
R. v. Tomlinson, 2014 ONCA 158, at para. 55.
Proper Notice of an Alibi
Failure to give proper notice of an alibi permits the trier of fact to draw an adverse inference when weighing the alibi.
Proper disclosure of an alibi has two components:
1. adequacy, and
That is, disclosure of an alibi should be given with sufficient particularity and early enough to permit the authorities to investigate the alibi meaningfully.
Notice need not come from the accused or his counsel. Notice from a witness will suffice. Nor must notice be delivered to the Crown. Notice to the police will suffice.
Improper notice can only weaken alibi evidence; it cannot exclude it.
R. v. Cleghorn, 1995 CanLII 63 (SCC),  3 S.C.R. 175, at para 3, 4.
The Disbelieved Alibi Versus the Concocted Alibi
A trier of fact may find that the alibi is untrue because it was not disclosed when it is reasonable to assume an innocent person would have disclosed it.
R. v. Hill (1995), 1995 CanLII 271 (ON CA), 102 C.C.C. (3d) 469 (Ont. C.A.), at pp. 477-479.
However, in the absence of evidence of concoction (deliberate fabrication) an alibi that is disbelieved has no evidentiary value.
R. v. Hibbert(2002), 163 C.C.C.(3d) (SCC).