Is reasonable cause reasonable cause sufficient to warrantless arrest?

The foregoing facts, accepted by the court, supplied ample "reasonable cause" under state law (former 836, subd. 3), and ample probable cause under the federal Constitution--the standards are identical (People v. Talley (1967) 65 Cal.2d 830, 835, 56 Cal.Rptr. 492, 423 P.2d 564)--to believe that defendant had committed a crime and thereby justify a warrantless arrest (Dunaway v. New York (1979) 442 U.S. 200, 208, 213-214, 99 S.Ct. 2248, 2254, 2257, 60 L.Ed.2d 824 (plur.opn.); see also id. at pp. 215-216, 99 S.Ct. at p. 2258 [requiring probable cause to effect arrest made for investigative purposes] ).