Having been in that situation, you need to have an attorney who is "hooked up" with the criminal justice system in the area where you have the incident. Unfortunately you can have a great lawyer who is from another part of the state who may not know the right people in the area that your situation occurs in.
I called a female friend who worked with lawyers and she called the "right" guy to handle my case. He knew everyone by first name, and my case was called first, all he said was keep your mouth shut and we will be out of here in a few minutes.
I hadn't done anything illegal just a rookie who made a huge mistake, all charges were dropped, but he was able to find out things that an outsider would never have been able to find out. The judge was a friend, and they were afraid I would sue the Dept, and the city, he was able to convince them that all I wanted was my permit and guns back, and I would not sue, it still took 18 months, but that's what happened.
Having an outsider come in, like in the movies, is unrealistic, it's like a private club, the court officers judges and cops all know each other, and who you know has a lot to do with how you are treated, and if the attorney can speak to people off the record.
In NYC you still have to go to a "Captains hearing" at 1 PP. after the case, "even if you convince the captain, that you are innocent you get your guns back" they determine if you get your license back. It's a lot of politics.
In my case the cop forgot half of what happened, he didn't take good notes, when I challenged some of the facts, the Captain saw that he was making it up as he went along, I can still hear him screaming at the "now plain clothes cop" from down the hall, after telling me I was free to go, and that they would notify me by mail.
It may be different where you live, but I have found that you need a lawyer who is in the county that you get arraigned in, which is hard to know in advance if you travel.
I ended up with a good friend "the attorney" and 30 yrs. later we still get a Christmas card every year even though I moved out of that hell hole.