An accused charged with a crime is entitled by way of defence to adduce evidence that a third party, not the accused, committed the crime. The evidence must meet the test of relevancy and must have sufficient probative value to justify its reception. In order to be relevant and probative, the evidence must connect the third person with the crime. If there is an insufficient connection between the third person and the crime, the evidence will lack the requisite air of reality: R. v. McMillan (1975), 23 C.C.C. (2d) 160, aff'd  2 S.C.R.824, at pp. 167-168; R. v. Grandinetti, 2005 SCC 5, 191 C.C.C. (3d) 449, at paras. 46-48.
 Evidence of a violent disposition or animus towards the deceased, standing alone, will not meet the required threshold. However, if there is evidence that the third person had a motive to commit the crime or threatened the deceased and had the opportunity to carry out the crime, then the evidence of propensity may have probative value: R. v. Murphy, 2012 ONCA 573, at para. 21; R. v. Baltrusaitis(1996), 31 W.C.B. (2d) 184; R. v. McMillan, at p.168.
 The evidence may be direct or circumstantial. Inferences based on the evidence may be drawn, but speculation is not permitted. The evidentiary burden on the accused is discharged if the defence shows that there is some evidence upon which a reasonable, properly instructed jury could acquit based on the proposed defence: R. v. Grandinetti, at paras. 47-48; R. v. Fontaine, 2004 SCC 27, 1 S.C.R. 702, at para. 70.
 This court has recently held that where an accused proposes to call direct evidence from a third party who is expected to admit culpability for the offences charged, this proposed evidence itself is sufficiently probative to establish an air of reality to the third party defence. In other words, the proposed direct evidence of the third party represents the requisite nexus between that third party and the crime, and it is an error to require the accused to show more before allowing the third party witness to be called: R. v. Murphy, at paras. 20-23.