Legality
In the 1931 Near v. Minnesota decision, the United States Supreme Court held that laws limiting what could be published, called prior restraint, infringed on the freedom of the press guaranteed by the First Amendment to the Constitution. "The fact that the liberty of the press may be abused by miscreant purveyors of scandal", wrote Chief Justice Charles Evans Hughes,"does not make any the less necessary the immunity of the press from previous restraint." Later the Court would allow a limited exception for national security purposes, in the Pentagon Papers case, New York Times Co. v. United States.
In the early 1980s a series of cases established the right of the press to cover all aspects of criminal proceedings in court. The first, Richmond Newspapers v. Virginia, held that the right to be informed about government action was specifically protected by the Constitution. Judges may still close criminal court proceedings to the media if they believe that coverage would create a "substantial probability" of denying the defendant his or her right to a fair trial, but must state their reasons for doing so on the record.
With this underlying law, no defendant had challenged the constitutionality of the perp walk prior to John Lauro. Despite criticisms that it undermined the presumption of innocence, defendants who had been convicted or pled guilty never claimed their rights had been violated by the perp walk, and could not claim injury to reputation from it. Lauro, who had been perp-walked only to have the charges later dropped, was the first claimant to have standing.
Read more about this topic: Perp Walk