Evidence obtained properly for one purpose may be used for another

R. v. DeJesus, 2010 ONCA 581 deals with a number of issues. One is whether DNA lawfully obtained in connection with the investigation of one offence may be used in the investigation of another. The answer is yes:

[9]              Finally, at a policy level, we agree with what Ewaschuk J. said in his ruling, namely:

Where the accused's DNA is lawfully obtained, I find no policy justification in foreclosing the right of the police to use the accused's DNA for comparison purposes in subsequent unrelated investigations, particularly where the offence in respect of which the DNA was lawfully seized resulted in a conviction.