4. The jury will have the final decision on 2nd degree murder or manslaughter.
The judge will probably advise the jury that they can bring in a verdict of guilty of 2nd degree murder or guilty of manslaughter. That gives the jury an option short of setting him free or sending him to prison for life.
I would much rather see him get life for murder; but, manslaughter keeps him locked up for up to 30 years.