The appeal to the state Supreme Court is automatic for all death penalty cases. The appeal argues, among other things, the trial judge made faulty rulings on evidence, and that the massive publicity denied Peterson a fair trial.
It could be years before the appeal is resolved. It has been eight years since Peterson was found guilty of suffocating his pregnant wife and dumping her body in the San Francisco Bay. Peterson has always maintained his innocence.
The Associated Press contributed to this report.