Heart of a killer / David Rosenfelt.

Jamie Wagner is a young lawyer who is happy to be flying under the radar at a large firm doing background research for the partners. It's not that he isn't smart. He is. It's just that hard work, the whole legal world, isn't really his thing. Underachiever? Yes. Content? At least until the firm puts him on a case that turns his whole world upside down. Sheryl Harrison has served four years of a thirty-year murder sentence for killing her husband who she claims abused her and her daughter Karen. The case is settled. There shouldn't be anything for Jamie to do--except Karen is sick. She has a congenital heart defect and will die without a transplant, and her rare blood type makes the chance of finding a matching donor remote. Sheryl wants to be that donor, and Jamie is in way over his head. Suicide, no matter the motive, is illegal, and Sheryl is put on suicide watch. Jamie's only shot at helping Sheryl and saving Karen is to reopen the murder case, prove Sheryl's innocence, and get her freed so that she can pursue her plan on her own.