What is the test for establishing intent in a criminal case when a defendant has committed an uncharged act of violence against another defendant?

The least degree of similarity between the uncharged act and the charged offense is required in order to prove intent. (People v. Ewoldt (1994) 7 Cal.4th 380, 402.) The recurrence of similar results tends " 'to negative accident or inadvertence or self-defense or good faith or other innocent mental state, and tends to establish (provisionally, at least, though not certainly) the presence of the normal, i.e., criminal, intent accompanying such an act.' " (Ibid.) In order to be admissible to prove intent, the uncharged misconduct must be sufficiently similar to support the inference that the defendant " ' "probably harbor[ed] the same intent in each instance." ' " (Ibid.)