Only an "accused" has a Sixth Amendment speedy trial right. Under U.S. v Marion, the U.S. Supreme Court has defined an "accused" as one who is subject to "formal indictment or information or else the actual restraints imposed by arrest and holding to answer a criminal charge."

In applying U.S. v Marion to a California case, the California Supreme Court has held in Serna v Superior Court that the federal speedy trial right attaches, in misdemeanor cases, when an individual is arrested or when the misdemeanor complaint is filed, which ever event is first. However in California felony cases, the court applies People v Martinez, and the federal speedy trial right attaches after the preliminary hearing when the defendant is bound over for trial, or when an indictment is filed. The filing of a felony complaint itself is not sufficient to trigger the protection.

The U.S. Supreme Court in Barker v. Wingo, has identified four factors which are applied on a case by case basis:

  • Length of the delay;
  • Reason for the delay;
  • Defendant's assertion of the right; and
  • Prejudice to the defendant. Prejudice may be shown by loss of a material witness or other material evidence, or fading memory caused by lapse of time.

A problem when applying federal speedy trial analysis is the concept of "presumptively prejudicial." Within the context of federal case law, the term is used in two different ways. The first refers to the amount of delay that will be deemed unreasonable enough to "trigger" the Sixth Amendment analysis. Because, under Doggett v U.S., the Court held, not every delay in the prosecution of a case, even if prejudicial, will violate a defendant's right to a speedy trial. The "people" only have to show that defendant was prosecuted with "customary promptness." The second use of the term refers to a delay that is long enough to warrant a "presumption" that the defendant has been "prejudiced" in some way that cannot be evidenced and therefore requires a dismissal without the burden of a specific showing of prejudice.

In Serna v Superior Court, the California Supreme Court held that a misdemeanor defendant need not demonstrate "actual prejudice" as a prerequisite to a Barker v Wingo hearing if the delay in the prosecution exceeds one year.

The U.S. Supreme Court has stated that a showing of prejudice is not a necessary requirement to establishing a violation of the Sixth Amendment. However, if actual prejudice cannot be shown, the underlying reason for the delay becomes the crucial question in the over arching analysis. If the government has prosecuted with reasonable diligence or "customary promptness," the delay is therefore not lengthy. Under those circumstance there will generally not be a Sixth Amendment violation without a showing of actual prejudice to the defendant. However, if the delay in prosecution was either intentional or in bad faith, dismissal will almost always be required, even if the delay is not as long and whether or not there is prejudice. However, in the case of a negligent failure to prosecute, the case for dismissal, even in the absence of prejudice, becomes stronger as the length of the delay increases. Therefore, a dismissal is generally warranted even if the delay is merely the result of administrative misfeasance or simple negligence on the part of the government.