Civilians are people that are too lazy, too stupid, or too high to join or be drafted even into the marines (wow). They live in big cities on planets nobody cares about except the UNSC. They drive worse than marines (again, wow) and are usually the covenant's first targets. In fact, the covenant doesn't consider them a threat at all, so they just capture them and use them for target practice, which is against the Geneva convention, but who really listens to that anyways? However all UNSC personel, even SPARTANs, were civilians at some point, so it is unfair to call them all lame. Another reason is that they can actually use a gravity hammer without killing themselves. Still, they can't fight
worth a crap but still use military grade weapons in a futile attempt to kill the covenant. All civilians answer to the UEG, which means they pay excessive taxes to fund useless wars, work at dead end jobs, and have to listen to useless
polititians and Glenn Beck rant on fox news every night (I pity them).
The police, also known as "da fuzz", "five 'o", "the cops", or "those guys who sit around eating doughnuts all day", are the civilian's law enforcement (yeah, right). They pull you over for rediculous reasons, give you tickets, and arrest you for whatever rediculous reason while two people shoot each other a few feet away. They are what the noobs call "0p". They wear crappy armor, and die very easily, especially against the covenant. But this has not stopped them from fighting on Harvest, Arcadia, other planets nobody cares about, and earth, where they "tried" to "help" the Rookie in New Mombasa. However, they can be corrupt. A police officer tried to kill the Rookie in New Mombasa because he "knew too much". However, the officer was suddenly eaten by a swarm of drones (not that Rookie couldn't have handled it). In short, Police are there for the public's protection, but I'd rather take my chances with the covenant, and remember kids crime does not pay (actually, it does. Why do you think criminals are so rich? Take George Bush, Snoop Dog).
The covenant say resistance is futile, but that didn't stop a few teenagers from grabbing military grade weapons and becoming a terror called the "Wolverines". These kids had watched Red Dawn too much, and thought they could just pwn their way through a legion of grunts. They thought right. However, the nearby legion of Elites didn't take kindly to this and pwned them all. The end.