SAN FRANCISCO — Frustrated by 500-page briefs in capital habeas corpus cases, the California Supreme Court issued its own 120-page ruling Thursday laying out strict new limits and warning of sanctions if they’re not followed.

The court harshly criticized the defense lawyers in In re Reno, 12 C.D.O.S. 10049, labeling various portions of their petition “untimely,” “improper,” “patently meritless,” “grossly misleading” and based on “stock justifications.” But it stopped short of issuing sanctions, as it had threatened to do before argument in the case, which had caused a storm in the capital defense bar. Instead, the court cautioned that violating its new rules, which include a 50-page limit on successive habeas petitions, could lead to sanctions and State Bar discipline in the future.