In a rare unanimous decision, the Supreme Court ruled on Tuesday that a Muslim prisoner in Arkansas must be allowed to grow his beard for religious reasons.

The ruling was a "huge win for religious freedom," the co-counsel in the case declared.

"This is a victory not just for one prisoner in Arkansas, but for every American who believes and wants the freedom to act on those beliefs," said Eric Rassbach, deputy general counsel for the Becket Fund for Religious Liberty. "No religion is an island."

The Muslim inmate Abdul Muhammed claimed his religion forbade him from cutting his beard. However, the Arkansas Department of Corrections forbids facial hair, with only medical exceptions: those with certain skin conditions are allowed a beard of 1/4 inch in length.

In a compromise, Muhammed proposed to keep his beard at 1/2 inch length, but the prison system denied his request. He then filed a lawsuit, but met defeat at a federal trial court and the 8th Circuit Court of Appeals.

He then sent a hand-written petition for injunction to the Supreme Court, which agreed last March to hear his full appeal.

The department had argued that beards posed a security threat, allowing the possibility of prisoners hiding contraband items and also using the beards as a disguise if they escaped prison.

However, the department failed to prove that its policy met the least restrictive means of maintaining prison security while respecting the religious freedom of prisoners, the Court said.

It determined that the department violated RLUIPA, or the Religious Land Use and Institutionalized Persons Act, which protects the freedom of prisoners to practice their religion peacefully.

"Although we do not question the importance of the Department's interests in stopping the flow of contraband and facilitating prisoner identification, we do doubt whether the prohibition against petitioner's beard furthers its compelling interest about contraband. And we conclude that the Department has failed to show that its policy is the least restrictive means of furthering its compelling interests," the Court said.

The justices also pointed out that many states and federal prison systems allow inmates to grow 1/2 inch beards, thus undermining the claim of the Arkansas prison system that its mandate was the least restrictive means necessary to maintain security. According to the Becket Fund, 43 prison systems allow beards of 1/2 inch length and 41 systems allow even longer beards.   

"What the Supreme Court said today was that government officials cannot impose arbitrary restrictions on religious liberty just because they think government knows best," Rassbach said.

"Where government can accommodate religion, it ought to."

Many different religious organizations supported Muhammed's case. Amicus briefs were filed on his behalf by the U.S. Conference of Catholic Bishops, various Jewish organizations, the International Mission Board for the Southern Baptist Convention, and many Islamic scholars, in addition to the U.S. Government and the American Civil Liberties Union.