Justice Anthony M. Kennedy said federal judges have an important duty in considering whether defendants’ rights are protected, but that judges must honor the high obstacles the Supreme Court has set before second-guessing and overturning a conviction.

“Confidence in the writ [of habeas corpus] and the law it vindicates [is] undermined if there is a judicial disregard for the sound and established principles that inform its proper issuance,” Kennedy wrote in one of the cases, Harrington v. Richter .

“That judicial disregard is inherent in the opinion of the Court of Appeals for the 9th Circuit.”

Kennedy is the only veteran of the 9th Circuit on the Supreme Court and he serves as its designated justice. That Chief Justice John G. Roberts Jr. assigned the decision to Kennedy was another way to send a message, Hellman said.