When an accused has provided a statement to the police, the Crown must decide what use, if any, to make of that statement at trial. As discussed by Boswell, J., in R. v. Osborne, 2019 ONSC 839, beginning at para. 12:
Where an accused person has given a statement to the police, the Crown often chooses to introduce it into evidence as a substantive part of its case in chief. There may be a number of reasons for this: to introduce inculpatory utterances; to demonstrate the demeanour of the accused; to adduce utterances that the Crown seeks to prove false through other evidence; or to demonstrate the manner in which the accused responded to certain questions.
Other times the Crown will elect not to tender an accused's statement in its case in chief, but rather hold it for use in cross-examination should the accused decide to testify. Given the rule against case-splitting, however, as a general rule the Crown's use of the statement in cross-examination is "limited to impeachment by challenging oral testimony with material contradiction in the statement”…(citations omitted)