Shannon v. United States

Background

A man stopped by police in Mississippi shot himself, survived, and was charged with unlawful firearm possession. At trial he argued he was insane at the time and asked the court to tell jurors that a verdict of "not guilty by reason of insanity" would lead to involuntary commitment. The district judge refused that instruction, the jury convicted, and the federal appeals court affirmed. The Supreme Court took the case to decide whether federal law requires such instructions.

Reasoning

The Court asked whether the Insanity Defense Reform Act of 1984 forces judges to tell juries about the post-verdict consequences of an insanity acquittal, or whether federal practice requires it. The majority looked first to the Act’s text and found it only prescribes the form of the verdict, not an instruction about consequences. The Court rejected arguments based on similarity to the old District of Columbia rule and on a single passage of legislative history, and declined to invoke broad supervisory power. It emphasized the longstanding rule that jurors should decide facts without regard to possible consequences and concluded the requested instruction is not required.

Real world impact

As a result, federal trial judges generally need not explain to jurors what happens after an insanity verdict. Defendants who want such information may not obtain it routinely, although the Court left room for limited instructions to correct misstatements in the courtroom. The decision affirmed the defendant’s conviction and applies nationwide to federal courts.

Dissents or concurrances

Justice Stevens (joined by Justice Blackmun) dissented, arguing that informing jurors prevents wrongful convictions, that Congress expected the older practice to spread nationwide, and that defendants should be allowed to have the instruction.