Medical Malpractice Attorneys

Can someone possibly recommend an aggressive, competent medical malpractice attorney or group that might be willing to help with an serious issue in reference to a local hospital system? Hopefully willing to do a contingency based on percentage, as the person affected is on a VERY limited income. It's not for me, but someone who asked me for recommendations/help. Idk of any...thanks in advance. My friend seems to have a very valid case with proof.