In the process of dealing with the American criminal justice system over the last year, I have observed a couple of things about it. Some of them are the typical "this is different from television" things, and some are things that television doesn't touch. The way economics influences the justice system is one of these things.
I'm going to use my case as an example because it's the only one I'm familiar with.
Every day you go to court is a day that, if you don't work nights or don't work in the area, you don't work. Every day you go to court is, therefore, a day you may not get paid for unless you choose to use sick days or vacation time on it. Further, many employers will not be understanding of your situation. They may assume, even if they think you are not guilty, that your arrest displays some kind of irresponsibility and that perhaps you shouldn't be employed with them anymore, or they may have a policy about such things.
Early in my case, I was offered a deal. I was told that I could plead guilty to any one of the charges against me, pay a $100 fine, and receive 3 years summary probation. While this is harsh for the crimes I was accused of, it's a very good deal, especially when compared to the costs of fighting the charges.
In order to fight the charges, you need an attorney. If you're going to get an attorney, you have a number of options. You can go with a public defender, a person who is overworked, underpaid, and if you're accused of something minor, as I was, a public defender will not have much of any time for you. Your other option is to hire an attorney. This is expensive; many attorneys charge upwards of $50 per hour, although you may be able to find something cheaper. Typically, you will want to hire the best attorney you can afford, since this can make or break your case. I am lucky enough to have an attorney willing to take my case pro bono. Most people will not have this option, although there are some good attorneys willing to do this, or willing to work cheap because they have a large retainer from another client; I had a friend whose attorney was on a huge retainer from a group of legitimate businessmen, and so took on other work cheaply.
If you've gotten this far, and you decide to go to trial, you will have to miss more work. This gets tricky if your job likes to know how long you're going to be gone for, since trials run until they're finished rather than according to a schedule. Even if you're given an estimate, don't assume that it's accurate. I was initially told that my trial would be 3 days, maybe 5. I was in the LA area for 3 weeks, with the actual trial running 7 days. Technically you do not have to be present at your trial except during your own testimony, but it looks a lot better to the jury if you are. It will let them put a face to your name, and will help them think of you as a real person rather than a faceless criminal. To further make a good impression on the jury, you should dress nicely, something that can be expensive if you don't already own nice clothes.
At this point, between missed work and attorney's fees, you will probably be out more than $1000, or more than 10 times the cost of pleading out. The longer your trial goes, the more the cost increases, and the less money you're bringing in to pay for it. If there are unusual circumstances, the costs are likely to be even higher.
Some unusual circumstances would include providing for other responsibilities you may have, such as making sure someone can take care of your child or pet. Unusual circumstances in my case were mostly that I lived 2000 miles from the court, and so had to fly in and rent a car. Flying is tricky when you don't know your return date; I ended up having to buy two one-way tickets.
As with anything else, there are also minor expenses associated with going to court. First, there is the matter of food. Carrying food with you is an option, but if you're not staying at home during your trial, it becomes tricky. Courthouse food sucks, and everything else is even more expensive. You may have to get medication for the trial. I had to have sleeping pills, sunblock, and rescue remedy. Neither of these items are expensive, but they do add up. I also had to get a separate journal for the occasion, as I was worried about it being confiscated, and didn't want to lose any more stuff than I had to.
One of the ways to deal with the cost is to get a legal defense fund. I was lucky enough to have a friend start one for me. This is easier to do if your charges relate to something political rather than child sex abuse, for example. You can also run benefit shows or hold benefit parties for your legal defense. You will have to pay the band for their expenses, and you may have to front money for beer or snacks, but this can be well worth it, especially if you have a lot of community support or the band is popular. Again, how successful this is may depend on what the charges against you are, and there's no guarantee that you'll be able to cover all your costs this way.