How Does the Criminal Justice system work?
After being arrested, you will likely be "booked" (fingerprints and mug shots) and put into a holding cell or even sent to Jail. Should you post bail? For serious offenses, if you have the money and do not want to spend days or even months waiting for a trial, you should post bail.
A Bail bondsman will post it for you if you give him a non-refundable 10% of the bail or put your house up for collateral. If your offense is less serious, such as trespassing or disturbing the peace, you may want to consider waiting it out for your arraignment, (usually within 48 hours of arrest) since the Judge may give you "time served", then drop the case.
The next step is for the Police to finish their report and give it to the District Attorney or City Attorney. They will assign the case to a "filing D.A." who will decide if the case should be prosecuted as a felony, misdemeanor, or otherwise..
After they file the case, you (and your attorney if you have one) go to court to be arraigned. You normally plead "not guilty" and you will then have to come back for your trial or any pre-trial motions that your attorney or you may file.
In felony cases you also have the right to a preliminary hearing where you or your attorneys get to question the witnesses (which may include the police) and see if the Court believes there is enough evidence to "bind you over" for trial. Normally, there is. However, your attorney can use this hearing to find out just how strong the case is against you.
95 out of 100 cases that get past the preliminary hearing are resolved before trial by a "plea bargain" or by an attorney getting the case dismissed for lack of evidence or violations of the defendant's rights. A good attorney can usually either win the case or negotiate a plea bargain, keeping you out of jail unless you have prior convictions. However, you may be "on probation" for 2-5 years after the plea bargain.
If you win at trial, you get an "acquittal" and cannot be tried for that same crime again. (Double Jeopardy rule). If you do lose at trial, be prepared for the Judge to give you a harsher sentence than you may have gotten on a plea bargain