Probable Cause and the 4th Amendment

Although the Supreme Court has held that a probable cause hearing has to happen in a reasonable time, less than 72 hours, it also has ruled that such a hearing need not be an adversarial one. In other words, the ‘ex parte’ hearing in which the arresting officer filed the affidavit of complaint with the judge and during which the judge decided on bail and method of release, appear to sufficient to overcome any claims of 4th Amendment violations.

Although we conclude that the Constitution does not require an adversary determination of probable cause, we recognize that state systems of criminal procedure vary widely. There is no single preferred pretrial procedure, and the nature of the probable cause determination usually will be shaped to accord with a State’s pretrial procedure viewed as a whole. While we limit our holding to the precise requirement of the Fourth Amendment, we recognize the desirability of flexibility and experimentation by the States. It may be found desirable, for example, to make the probable cause determination at the suspect’s first appearance before a judicial officer, . . . or the determination may be incorporated into the procedure for setting bail or fixing other conditions of pretrial release. In some States, existing procedures may satisfy the requirement of the Fourth Amendment. Others may require only minor adjustment, such as acceleration of existing preliminary hearings. Current proposals for criminal procedure reform suggest other ways of testing probable cause for detention. Whatever procedure a State may adopt, it must provide a fair and reliable determination of probable cause as a condition for any significant pretrial restraint of liberty, and this determination must be made by a judicial officer either before or promptly after arrest.

Gerstein v. Pugh, 420 U.S. 103 (1975)