So my ultimate goal for this female character I'm working on is for her and her sister to turn their lives around. She's a criminal but didn't become one by choice and is at the point where she'll do whatever to get her and her sister a normal life again. The big bad she works for is really scary he has his hands in terrorist organizations he sells dangerous weapons to hostile nations. He is also involved in drugs and the sex trade which is how she and her sister ended up under his thumb. Now she's no saint and is even guilty of some heinous crimes that he ordered. However she's eventually at the point where she's will to make a deal and this is her pitch "The bastard ruined my life and all I want is a chance at a normal one so if you give me and my sister a pardon or whatever gives us that chance at a fresh start I'll do more than name names, and tell you where the bodies are I can tell you every cash, safe house he has this side of the continent I can list at least ten politicians he blackmail and what with, I can tell you everything." Now for her freedom is a big deal because she's been under his thumb for a very long time and never wanted this life so she's very serious when she approaches whoever with this. The.only problem though is that she's knowledgeable about the innerworkings but she doesn't know everything but it's still more than the good guys know so I'm wondering if this is a deal law officers would make. Also who'd be her best bet to make this kind of deal and what would be the terms? Because even though she's prepared to give him up she's only just now in a position to do so since its the first time she can honestly give his location because always moves around. So for her it's a big risk because she's not even sure of he'll be where he supposedly is for very long she's pretty much just going by a rumor when she makes this deal.
If this is the US she'd be dealing with the FBI (terrorism) and a US Attorney in a federal court. They would likely grant her immunity (and witness protection most likely) in exchange for her deposition and testimony. She would also prob have to allocute (spill her guts about every crime she's ever committed so there're no surprises under cross-examination by the defense). If the villain is as bad as you say he is the Justice Department would likely bend over backwards for her unless she's a serial killer or something. That would complicate things.
Thank you she's not a serial killer but she's not saint the best way to describe her position in the bad guy's organization is she's like the Baroness and the big bad is like Cobra Commander commander from G.I. Joe. If I could describe the situation it would be that in the simplest terms there's a gun pointed at her sister's head and she's expected to do whatever her boss wants if she wants her sister to survive.
She doesn't actually have to know everything about the organization to be useful to authorities. People who work in large organized crime rinks are very rarely, if ever, found guilty of everything their organization does. I think one mafia crime boss was only found guilty of tax evasion at the end of the day, despite the horrific murders his organization took part in under his orders. If her testimony is key to grant them some charge that would stick, it is well within the realm of possibility for authorities to grant her immunity for that testimony. Now, they probably won't grant her immunity from everything. If she was part of recruiting other young girls into the sex trade, then yes she might be granted immunity from charges related to that, but not necessarily murder. So consider that for a moment.
