I would not deindex anything. The search rankings are the bread and butter. The question is how do you leverage current traffic and use it to boost personal injury.
I would start by curating new content that aligns with the criminal justice content. Then take the criminal justice content and redirect it to your new content.
If you deindex, traffic will drop considerably and it will be like starting from scratch. If you redirect you may be able to pass link juice to your new pages while rankings start to increase for personal injury.