PENAL CODE SECTION
830.8. (a) Federal criminal investigators and law enforcement
officers are not California peace officers, but may exercise the
powers of arrest of a peace officer in any of the following
circumstances:
..............This subdivision does not apply to federal officers of the Bureau
of Land Management or the Forest Service of the Department of
Agriculture. These officers have no authority to enforce California
statutes without the written consent of the sheriff or the chief of
police in whose jurisdiction they are assigned.