Forgive me if this is a dumb question.
Could JM's lawyer ask, or even see, what evidence they have before having him go to police?
I believe there is some evidence that the lawyer can see. However, in cases like this, IMO, he's better off in jail. He's safer, the family's safer, everyone is safer. Though it may seem like a horror show to be in the national spotlight with such notoriety, it does provide JM some protection in terms of violation of rights. Every move that LE and the DA's office makes is under scrutiny and several LE agencies like FBI are breathing down local law officer's necks. They are going to have to be very careful in how they treat JM.
Also, JM seems to have an anger management problem, is careless, has poor judgement. Not the savvy sort that can survive well on the run. He is risking his friends and family's safety if they are harboring him, also subjecting them to possible charges. Really, he is more of a danger on the loose. If he were a friend of mine or a family member, I'd try hard to get him to turn himself in. Jail is not the worst thing in the world.