Sheriff
Sheriff Rex Langford usually spawns a day or two after doing the beer run for Jake. Jake will mention his arrival in one of his emails to you. On an existing save, the Sheriff will already be present if your game has progressed past this point. The Sheriff is mostly self-explanatory and will tell you what crimes you are being charged with, what is going to happen to you, and what you need to do.
Location
The Sheriff's station is located about 100m south of the gas station. The Sheriff will usually be found here, although he will patrol random areas of the map such as the junkyard, the residential area, and he will sometimes exit his vehicle and hang out near the gas station.
Crimes
Excessive Speed
DUI
Evading Arrest/Detention
Possession(Moonshine)
Reckless Driving
Hit and Run
Headlamps on Vehicle
Open Container
Theft(fuel)
Behavior
If you are committing a crime within the visibility range of the Sheriff, he will either pursue you on foot or attempt to initiate a traffic stop. The Sheriff will also pursue you if you have committed a crime in the past but managed to evade arrest.
Traffic Stop
Stopping is generally recommended because the Sheriff might let you off with a warning. Failing to stop will result in additional charges later on. After stopping your vehicle, the Sheriff will approach and tell you why you were stopped. In addition to the original reason for the stop, you will get charged with a DUI if you are drunk. If you are not drunk but have beer cans in or around your vehicle, you will either get a warning or a ticket for open container. If you are not arrested, the officer will hand you a ticket before leaving.
Arrest
If your crime is serious enough, the officer will attempt to get close enough to handcuff you. If you are handcuffed, he will bring you to his vehicle and transport you to jail. After a short time in jail, you will receive a citation you will need to pay within three days. Depending on how serious your crime is, your vehicle may or may not get impounded.
Tickets
Tickets exist in the form of physical objects given to you by the Sheriff. Tickets can be paid off by interacting with them and clicking the circled amount due. Failing to pay off a ticket after several days will result in an arrest warrant.
Impound
If you really screw up, your vehicle may get impounded. You can recover your vehicle by talking to the Sheriff when he is sitting inside the guard booth near the Sheriff's station.
What not to do
Don't ferment moonshine in a public area where the Sheriff might see you. If the Sheriff sees you near a bucket containing alcohol, you will be arrested and the bucket's contents will be emptied. The same applies to carrying or driving with crates of processed moonshine. Unlike your friends who sell it, you don't have a license to possess it.
Pay for your fuel after refuelling. Putting this off could result in a theft charge.
Evade arrest if you're carrying a load of moonshine. An evasion charge is probably cheaper than losing all of your moonshine to a traffic stop.
Pay off your tickets. If you have too many outstanding warrants, the Sheriff will show up to your home when you are sleeping and arrest you.