What is the test for probable cause in an arrest?

We turn next to appellants' contentions that their arrests were illegal for lack of probable cause. The applicable standard is well settled, namely, that "probable cause to arrest exists when an officer has knowledge of facts and circumstances 'sufficient to warrant a prudent man in believing' that an offense is being or has been committed." United States v. Rueda, 549 F.2d 865, 870 (2 Cir. 1977) (quoting Beck v. Ohio, 379 U.S. 89, 91 (1964)). Applying that standard to the facts of this case, we hold that there was probable cause for appellants' arrests.