What is sufficient to prove a conspiracy to commit a crime?

We turn first to the issue of agreement. "Evidence is sufficient to prove a conspiracy to commit a crime 'if it supports an inference that the parties positively or tacitly came to a mutual understanding to commit a crime. [Citation.] The existence of a conspiracy may be inferred from the conduct, relationship, interests, and activities of the alleged conspirators before and during the alleged conspiracy. [Citations.]' [Citation.]" (People v. Rodrigues (1994) 8 Cal.4th 1060, 1135.)

The parties "need not expressly agree at all: 'To prove an agreement, it is not necessary to establish the parties met and expressly agreed; rather, "a criminal conspiracy may be shown by direct or circumstantial evidence that the parties positively or tacitly came to a mutual understanding to accomplish the act and unlawful design." [Citation.]' [Citation.]" (People v. Johnson (2013) 57 Cal.4th 250, 264, original italics.)