Criminal defense law is a really wide-ranging niche of the legal profession, with all things having been considered and taken into account. It manages to cover a lot of different areas, which means that if you hire a lawyer that specializes in this field, you would be able to use them for quite a few legal cases that you might be fighting at any given point in time. One common kind of case that such lawyers fight has to do with drugs, so if you find yourself in a situation where you are unjustly accused of participating in the drug trade, then hiring an attorney that specializes in criminal defense might just be the best course of action for you to end up taking.
One thing that often happens in these cases is that you might be found with a small number of drugs that you had intended for personal use and nothing else, but despite this, the police might make you out to be some kind of a drug dealer by inflating the number of narcotics they found on your person. You can view on this page the implications of this sort of thing, but suffice it to say that it results in some pretty heavy jail times, and you would really struggle to find a way to get out of this terrible situation without a lawyer.
The great thing about criminal defense lawyers is that they have a tendency to be really good at showing the evidence for what it truly is. They can use their expertise to show that you are just a user and not a dealer, and this can result in some much better plea deals for you.