In Lorenson v. Superior Court (1950) 35 Cal.2d 49, the defendant was a police captain in the Los Angeles Police Department indicted for conspiracy to commit robbery, to commit assault with a deadly weapon, and to pervert or obstruct justice. (Lorenson, supra, 35 Cal.2d at pp. 50-51.)
In rejecting a claim of insufficient evidence to support the indictment, the court concluded that one could infer from the evidence that there was agreement among the defendant, other members of the police department, and criminal associates of Mickey Cohen to assault and rob the victim, Pearson.
The court further noted that there was evidence from which one could infer that the defendant and other police officers "were to furnish protection to the participants in the conspiracy by refusing to disclose the identity of Pearson's attackers, if they were arrested, and to effect their release from custody." (Id. at p. 57.)
After the robbery and assault, Cohen's associates were arrested (apparently by officers not involved in the conspiracy), but they were immediately released from the police station before Pearson could arrive to identify any of them, and the arresting officers were instructed not to talk about the incident. (Id. at p. 54.) Lorenson is an example of "a conspiracy with or among public officials not to perform their official duty to enforce criminal laws," an indictable offense at common law. (Id. at pp. 59-60.)