Evidence - Hand-writing. R. v. Megill
In R. v. Megill (Ont CA, 2021) the Court of Appeal the court set out the ways in which handwriting may be proven:
The Governing Principles
 At common law, proof of handwriting could be made by testimonial or circumstantial evidence. For example, a witness might testify that they saw the act of writing. Or they might give evidence of the circumstances leading up to or pointing back to the act of writing. In a similar way, a qualified witness may testify about the style of the handwriting which requires a comparison between known and the disputed writing: VII Wigmore on Evidence (Chadbourn Rev. 1978), §1991, at pp. 252-57.
 The common law also permitted the trier of fact, without the aid of experts, to compare handwriting samples when a proved or admitted standard used for comparison with the disputed writing was already properly admitted as evidence for other purposes. No document was admissible merely as a standard of comparison with the disputed writing: R. v. Abdi (1997), 1997 CanLII 4448 (ON CA), 116 C.C.C. (3d) 385 (Ont. C.A.), at para. 15, citing VII Wigmore on Evidence (Chadbourn Rev. 1978), §§1992-1994, at pp. 257-64.
 Under s. 8 of the Canada Evidence Act, R.S.C. 1985, c. C-5, handwriting may be proven by comparison, by expert or lay witnesses, of a disputed handwriting with one that has been proved to be genuine and which has been received in evidence for the purpose of comparison: Abdi, at para. 16.
 Section 8 does not oust the common law rule. The section does not preclude a trier of fact from comparing disputed handwriting with admitted or proved handwriting in documents which are properly in evidence and drawing available inferences: Abdi, at paras. 22, 23 and 25.