What is the test for admissible evidence of a crime where a defendant is accused of carrying out a robbery using a knife?

In order for evidence of other crimes to be admissible, there must be some degree of similarity between the charged crime and the other crime, but the degree of similarity depends on the purpose for which the evidence was presented. The least degree of similarity is needed when, as here, the evidence is offered to prove intent. (People v. Jones, supra, 51 Cal.4th at p. 371.) Here, the evidence showed that the two incidents were only minimally similar: In one, defendant entered a store and used a knife, which he brought with him, to commit a robbery. He did not injure anyone in the incident. In the other, defendant entered the residence of someone he apparently knew and, under circumstances that were not established with any certainty, used a knife to kill the occupant and stole some money and other items. There was no evidence that defendant brought the knife with him. The weapon used in the incident was never found. The victim's widow testified that a set of chef's knives was missing from the kitchen. Thus, the use of a knife was the sole point of similarity between the two incidents that was established by the evidence, and the absence of evidence that defendant brought the knife with him tends to limit the probative value of the evidence that in the prior incident, defendant carried out a robbery with a knife he had brought with him.