435 U.S. 850 (1978)
In February 1970, Jeffrey R. MacDonald served as a captain in the Army Medical Corps at Fort Bragg, North Carolina.1 On February 17, his wife and two daughters were murdered in his quarters, and he sustained injuries.2 Military police, the Army Criminal Investigation Division, the FBI, and local police immediately investigated the crime.3
On April 6, 1970, the CID informed MacDonald he was under suspicion. He was relieved of duties and restricted to quarters.4 On May 1, the Army charged him with the murders under the Uniform Code of Military Justice.5 An Article 32 investigation followed, and the investigating officer recommended dismissal of the charges along with further investigation of a female suspect.6 On October 23, 1970, the commanding general dismissed the charges.7 In December 1970, MacDonald received an honorable discharge for hardship reasons.8
After his release, the CID continued its investigation at the Department of Justice's request, producing extensive reports through 1973.9 In August 1974, the government presented the case to a grand jury in the Eastern District of North Carolina.10 On January 24, 1975, the grand jury indicted MacDonald on three counts of first-degree murder.11
The district court denied MacDonald's pretrial motion to dismiss the indictment on speedy trial grounds on July 29, 1975, and scheduled trial for August.12 The Fourth Circuit stayed the trial, permitted an interlocutory appeal, and reversed the district court's denial, ordering dismissal of the indictment.13 The Supreme Court granted certiorari in 1977 to address the jurisdictional question.14
Whether a defendant, before trial, may appeal a federal district court’s order denying his motion to dismiss an indictment because of an alleged violation of his Sixth Amendment right to a speedy trial?15
The principle of finality embodied in 28 U.S.C. § 1291 limits appellate jurisdiction to final decisions of the district courts.16 Interlocutory or piecemeal appeals are disfavored in criminal cases.17 An exception for collateral orders exists when the order (1) fully disposes of the disputed question, (2) resolves an issue completely collateral to the merits, and (3) involves an important right that would be lost if review must await final judgment, as articulated in Cohen v. Beneficial Industrial Loan Corp. and applied to double jeopardy claims in Abney v. United States.18 Speedy trial claims under the Sixth Amendment do not satisfy these criteria because their resolution depends on facts developed at trial, they are intertwined with the merits, and they do not confer a right not to be tried.19
No. The district court's denial of the motion to dismiss on speedy trial grounds did not constitute a complete and final rejection of the claim.20 Nor was the issue collateral to the merits or one that would be irreparably lost without immediate review.21
Because prejudice under the Barker v. Wingo factors remains speculative before trial and the claim is not finally resolved until after the facts are developed at trial, the order fails the first Cohen criterion.22 The speedy trial issue is intertwined with events at trial rather than separable from the question of guilt, failing the second criterion.23 Unlike double jeopardy, the Speedy Trial Clause protects against delay before trial and does not encompass a right not to be tried that must be vindicated immediately, failing the third criterion.24
The Court of Appeals therefore lacked jurisdiction to entertain the interlocutory appeal, and its judgment directing dismissal of the indictment must be reversed.25