In the case of Shadwick v. City of Tampa, 1971, the U.S. Supreme Court ruled that non-lawyer court clerks could issue arrest warrants if they were capable and competent to determine probable cause. The case arose when a city clerk in Tampa issued an arrest warrant for William Shadwick without consulting a judge or prosecutor first. Shadwick challenged this practice as unconstitutional, arguing that only judges should be able to issue such warrants under the Fourth Amendment's protection against unreasonable searches and seizures. The Supreme Court disagreed with him by a vote of 7-2, stating that there was no constitutional requirement for issuing officers to be lawyers or have legal training so long as they are "neutral and detached" from law enforcement activities and capable of determining whether probable cause exists based on facts presented to them.

In the dissenting opinion for Shadwick v. City of Tampa, Justice Harlan argued that municipal court clerks should not be considered "magistrates" under federal law because they lack legal training and independence from police influence. He contended that allowing such individuals to issue arrest warrants could lead to abuses of power and violations of citizens' Fourth Amendment rights against unreasonable searches and seizures. Furthermore, he expressed concern about potential conflicts of interest since these clerks are often employees or appointees of local law enforcement agencies. In his view, only those with sufficient legal knowledge and impartiality should have the authority to decide whether probable cause exists for an arrest warrant.