What is it that you need to brainstorm? I read the short summary you provided in your reply to Robert Waltz , and I see some interesting but seemingly disparate ideas:

1. Your protagonist is an abuse survivor diagnosed with DID (this diagnosis is now controversial both legally and medically, and it's also an illness that has been portrayed many times and in many ways in fiction and film. It's a bold choice to tackle it, since its many portrayals will challenge any writer to show it in a new way.)

2. The people close to her are all murdered for a reason I can't discern by the MS-13 gang. She becomes a prosecutor and faces them (is she actually prosecuting them, or is she "facing them" in a different way?) As a reader, I immediately wonder why the gang is targeting her and how it relates to her past. If she is indeed "facing" them, wouldn't it be a pretty big conflict of interest? I wonder if a lawyer whose friends had been (allegedly) murdered by the gang members in question would be allowed to be part of the prosecution team at all.

I have a few questions, to start. You don't have to answer them; they're just for reference.

How likely is it that the same four members would be captured and would face the same judge again? (I am not terribly familiar with the legal system, I'll be honest.)

What drove your protagonist to become an ADA? How does her diagnosis affect her work and daily life, if at all? Are the people around her aware of her diagnosis, and does it affect the way she's treated? How does it tie into the larger plot? What is the larger plot?

What is at stake for your protagonist? Does she have anyone she cares about in her life at the moment who might be at risk?

This strikes me as an adult contemporary legal thriller type of book. It sounds intriguing. I threw out some questions because I know that when I try to answer questions about my own universes, it always helps me make sense of things. If you already know the answers to all of these, then you've probably got this idea in the bag already! If not, I'm sure the many wonderful prompts here at OctoPrep will help things take shape for you!