The U.S. Supreme Court case O'Lone v. Estate of Shabazz (1986) dealt with the issue of religious freedom within prison systems, specifically regarding Muslim inmates' rights to attend Jumu'ah, a weekly Islamic congregational service held on Fridays. The plaintiffs were two Muslim prisoners who claimed that their First Amendment rights had been violated by New Jersey's Leesburg Prison Complex policies which prevented them from attending these services due to work assignments and security concerns. In a 5-4 decision, the court ruled in favor of the prison administrators stating that while prisons must accommodate for religious practices, they are not required to do so when it would compromise legitimate penological objectives such as maintaining order and discipline or running an efficient institution. The ruling emphasized that courts should defer to professional judgment of prison administrators in matters related to institutional operations.

In the dissenting opinion for O'Lone v. Estate of Shabazz, Justice Brennan, joined by Justices Marshall and Stevens, argued that the majority's decision failed to adequately protect prisoners' religious rights as guaranteed by the First Amendment. They contended that a prison regulation infringing on these rights should be subject to strict scrutiny rather than a reasonableness test. The dissenters believed that this would ensure such regulations are narrowly tailored and serve compelling state interests - criteria they felt were not met in this case where Muslim inmates were denied access to Friday afternoon congregational services due to work requirements. Furthermore, they criticized the majority's reliance on Turner v. Safley (1987), arguing it was inappropriate given its focus on prisoner-to-prisoner communications rather than religious freedoms.