actually the issue of sheriffs powers has been debated frequently. it seems to be a confusing issue for most, even the sheriff themselves. I have done some research into to this issue because we actually had deputies patrolling our community on certain holiday's to assist us. First the SHERIFF himself is the chief law enforcement officer for his county. a deputy has all the same powers of arrest within his county as a police officer would have in his city/town. There are limitations though. The sheriffs right to arrest is not necessarily based on statute. it is based on common law and rights and powers granted to sheriffs over centuries. a deputy DOES have the right to stop a motor vehicle for a CMVI. a deputy CAN legally issue a citation for a CMVI. the breach of the peace ONLY part comes into to play with motor vehicles though. he may however summons for the offense. I'll try to find the case law I looked under and post it here. it is very interesting though if you research it.