What is the propriety of an arrest for a violation of federal law by a state peace officer?

The propriety of an arrest for a violation of federal law by state peace officers is determined by reference to state law. (Miller v. United States (1958) 357 U.S. 301, 305, 78 S.Ct. 1190, 1193, 2 L.Ed.2d 1332.) A peace officer may arrest in California (1) when a public offense is committed in the officer's presence, (2) when a person has committed a felony, and (3) when reasonable cause exists to suspect a person has committed a felony, whether or not a felony has, in fact, been committed. (Pen.Code, 836.)