In the case of Holbrook v. Flynn, 1985, the U.S. Supreme Court ruled that a defendant's right to a fair trial was not violated by visible security measures in courtrooms such as uniformed guards. The issue arose when Thomas J. Flynn appealed his conviction for armed robbery on grounds that four uniformed state troopers were seated in the first row of the spectator section during his trial which he claimed created an unfair prejudice against him among jurors and infringed upon his constitutional rights under the Sixth Amendment (right to fair trial) and Fourteenth Amendment (equal protection). However, after considering previous rulings regarding courtroom security measures like shackling or prison uniforms for defendants, it was determined that these overt displays did not inherently prejudice a jury against a defendant unless they were excessive or their necessity wasn't justified by concerns over safety or escape risk. Therefore, since there was no explicit indication suggesting any inherent prejudicial effect from having uniformed officers present at trials nor evidence showing specific bias towards Flynn due to this arrangement in his case specifically; it was concluded that such arrangements do not violate constitutional rights.

In the dissenting opinion for Holbrook v. Flynn, Justice Marshall argued that the presence of uniformed security officers in a courtroom during trial could potentially prejudice jurors against the defendant. He believed this practice violated a defendant's right to a fair trial as it might suggest to jurors that the accused is dangerous or guilty before any evidence has been presented. Furthermore, he disagreed with majority’s view that visible security measures are inherently prejudicial only when they single out a particular defendant, stating there was no logical reason why such an inference would not arise whenever guards are present in courtrooms regardless of their number or appearance. Therefore, according to him, courts should scrutinize all uses of identifiable security personnel and consider whether less conspicuous measures could have achieved similar results without risking unfairness towards defendants.