Martinez v. Illinois
The Supreme Court summarily reversed the Illinois Supreme Court, ruling that a man's trial-court acquittal on aggravated battery and mob action charges permanently barred a retrial, because jeopardy attached the moment the jury was sworn in.
The decision reaffirms a bright-line rule that has governed criminal trials for decades: once a jury is sworn, a defendant cannot be forced through the ordeal of a second trial after being acquitted, even if prosecutors caused the acquittal by refusing to present evidence.
“jeopardy attaches when the jury is empaneled and sworn.”
The Court's bright-line rule for when a criminal defendant becomes protected against double jeopardy.
How it got here: The Illinois Appellate Court and Illinois Supreme Court allowed the State's appeal of the acquittal, ruling jeopardy never attached; Martinez sought Supreme Court review.
The Case in Depth
What happened
Illinois charged Esteban Martinez with aggravated battery and mob action in 2006. His trial was delayed for years while prosecutors repeatedly failed to locate their two key witnesses despite multiple continuances and subpoenas. When the trial finally began in 2010 and the witnesses still had not appeared, prosecutors told the court they would not participate, and after the jury was sworn, the trial court entered a directed not-guilty verdict.
The question before the Court
After prosecutors refused to present any evidence once the jury was sworn and a judge acquitted the defendant, could Illinois still appeal and try him again?
Why it matters
Prosecutors cannot avoid the consequences of being unprepared for trial by refusing to present evidence and then appealing an acquittal. The ruling protects defendants from being tried twice for the same crime and reminds prosecutors that once a jury is sworn, there is no do-over if the state's witnesses fail to show up.
What changes now
The Supreme Court's reversal is final on the double jeopardy question: Martinez cannot be retried for the aggravated battery and mob action charges. The case is sent back to Illinois courts only to carry out proceedings consistent with this ruling, not to reconsider whether a retrial is permitted. The decision leaves undisturbed the broader legal framework governing when jeopardy attaches and when acquittals bar retrial.
What this does not decide
The Court noted it was not deciding the scope of possible narrow exceptions to the jeopardy-attachment rule, such as cases involving a court lacking authority to hear the case or an acquittal obtained through fraud, since those issues were not raised by Martinez's case.
How the Court got there
The legal reasoning, step by step
- The Court applied its long-settled bright-line rule that jeopardy attaches the moment a jury is empaneled and sworn, meaning that from that point on the defendant is formally 'put to trial' and protected against being tried twice for the same charge.
- The Court explained that Illinois had misread an earlier case, Serfass v. United States, as allowing a flexible, case-by-case inquiry into whether a defendant was genuinely at risk of conviction. In fact, Serfass endorsed the same fixed rule: jeopardy attaches when the jury is sworn, full stop.
- Because Martinez's jury had been sworn before the State refused to present evidence, the Court found jeopardy had unquestionably attached, regardless of whether the State ever intended to put on a real case.
- The Court then asked whether the way the proceeding ended barred a retrial, applying the settled rule that a genuine acquittal — any ruling that the prosecution's evidence was insufficient to prove guilt — can never be appealed or retried.
- The Court held that the trial judge's grant of a directed not-guilty verdict was a true acquittal regardless of what label the judge used, because it rested on a finding that the State's evidence (or lack of it) could not support a conviction.
Doctrinal impact
Cases affected by this decision
Reaffirms Crist v. Bretz (437 U. S. 28)
Reaffirms the rule that jeopardy attaches when the jury is empaneled and sworn.
Distinguishes Serfass v. United States (420 U. S. 377)
Clarifies that Serfass did not create a flexible test for when jeopardy attaches, contrary to Illinois's reading.
Reaffirms Downum v. United States (372 U. S. 734)
Relies on Downum's rule that lack of witnesses rarely justifies ending a trial after jeopardy attaches.