The Spreigl Problem: Minnesota’s Other-Acts Doctrine Is Unconstitutional and Creates an Unfair Trial Penalty

Imagine a defendant charged with a single burglary. Under Spreigl, the State can tell the jury about three uncharged burglaries from a decade ago—even if the defendant was never charged, never convicted, and denies them. That defendant is now on trial for four crimes, not one. That is Spriegl evidence in a nutshell.

Spreigl Evidence in Minnesota: A Constitutional Crisis Disguised as an Evidence Rule

Minnesota’s “Spreigl evidence” doctrine—our local name for evidence of a defendant’s “other crimes, wrongs, or acts”—has long been justified as a narrow exception to the general prohibition against propensity evidence. The theory is familiar: evidence of prior misconduct may be admitted not to show a defendant is the kind of person who commits crimes, but to illuminate specific issues such as intent, identity, knowledge, or absence of mistake.

That’s the doctrine on paper. In reality, Spreigl evidence functions as one of the most powerful tools the State has to tell a jury: This person is guilty because they’ve done bad things before.

Even Minnesota’s own caselaw admits this danger. In State v. Spreigl, the Minnesota Supreme Court warned that prior-bad-acts evidence carries a “strong inference” of guilt by character—so strong that it may cause jurors to convict a defendant simply because they believe he “escaped punishment from other offenses.” Yet six decades later, Minnesota continues to liberally rely on a rule its own judges described as constitutionally perilous.

The result is a doctrine that strains, if not shatters, foundational constitutional principles: the presumption of innocence, the right to due process, and the Sixth Amendment rights to testify and present a defense. It also fuels something judges rarely acknowledge out loud: the trial penalty—the reality that defendants are punished for insisting on their right to a trial.

The Presumption of Innocence Meets Its Match

The presumption of innocence is supposed to be an immovable burden on the State. A defendant begins trial cloaked in innocence, and the prosecution must prove every element beyond a reasonable doubt.

Spreigl evidence embarassingly destabilizes that bedrock. Once jurors hear about alleged past misconduct—especially uncharged or unproven misconduct—the entire trial shifts gravitational pull. The jury is no longer deciding whether the State proved this crime; they are deciding whether the defendant is the kind of person who does those things.

That is the exact inference the rules of evidence are supposed to prohibit. Spreigl simply repackages it under the magic words “intent,” “identity,” “common scheme,” or “absence of mistake.”

Minnesota’s appellate courts insist that safeguards exist:

• advance written notice,

• clear-and-convincing proof of the prior act,

• specific relevance to a material issue, and

• a balancing test to ensure probative value outweighs prejudice.

  
  

These are safeguards only in name. In real courtrooms, they function as a rubber stamp. Once the prosecutor recites the right incantation, the evidence almost always comes in. And once it comes in, no limiting instruction can unring the bell. Jurors are human. Humans naturally assume that past behavior predicts present behavior. The Minnesota Supreme Court warned of this exact psychological trap in Spreigl itself.

Put bluntly: Spreigl evidence allows the State to try a defendant for their entire alleged life history, not the charged offense. That is the antithesis of due process.

We would never tolerate a prosecutor charging a defendant with ten crimes, proving one, and then asking the jury to convict on all ten anyway. Yet Spreigl accomplishes the same thing through the back door: it imports uncharged, unproven allegations into the trial and invites the jury to treat them as de facto counts.

The Due-Process Problem: A Trial Within a Trial

Spreigl evidence does not merely “risk” prejudice; it creates a trial within a trial.

Imagine a defendant charged with a single burglary. Under Spreigl, the State can call witnesses to testify about three other alleged burglaries from a decade ago—no charges, no convictions, maybe no police reports. The defendant must now defend four cases at once, even though only one is actually in the complaint.

This forces the defense to:

• investigate collateral allegations mid-trial,

• respond to claims for which there may be little or no discovery, and

• combat emotional testimony that the State never had to prove beyond a reasonable doubt.

  
  

The legal standard for admitting Spreigl evidence—“clear and convincing evidence”—is dramatically lower than proof beyond a reasonable doubt. Yet in practice, Spreigl often becomes the emotional centerpiece of the State’s case. The jury may remember the sensational “other acts” far more clearly than the sparse evidence on the charged offense.

Minnesota courts acknowledge these hazards in the abstract but rarely grapple with their constitutional implications. If the presumption of innocence means anything, it must mean that a defendant cannot be convicted because of unrelated past conduct. And if due process means anything, it must mean that a defendant cannot be forced to litigate uncharged allegations in the middle of trial just to preserve their liberty.

Spreigl effectively rewrites the criminal complaint mid-trial—without the protections of charging, notice in the constitutional sense, or proof beyond a reasonable doubt.

The Silent Casualty: The Right to Testify

The constitutional harm of Spreigl evidence is not limited to the presumption of innocence; it directly chills the Sixth Amendment right to testify.

Minnesota courts take an exceptionally broad view of cross-examination once a defendant takes the stand. A testifying defendant is said to “waive his privilege concerning all questions bearing on the crime charged,” and courts have permitted questioning that references other alleged misconduct if it is deemed “relevant and pertinent.” In practice, that often means the State can do through “impeachment” what it could not do through Spreigl: get prior bad acts in front of the jury.

This creates a cruel paradox:

• A defendant has a constitutional right to testify.

• But exercising that right exposes them to impeachment with prior bad acts—sometimes the exact same acts the prosecution was not permitted to admit as Spreigl in its case-in-chief.

  
  

So the defendant is effectively punished for speaking.

This dynamic forces many defendants to remain silent, even when they have a compelling explanation for what happened, because the cost of testifying is too high. The State can float unrelated accusations under the guise of impeachment, and jurors inevitably conflate that questioning with guilt. A right that evaporates the moment it is exercised is not a “right” at all.

The same pressures extend to defense witnesses. If calling a witness opens the door to impeachment about unrelated misconduct or prior convictions, the defense may strategically decline to present helpful testimony. The U.S. Supreme Court has held that the right to present witnesses is a “fundamental element of due process.” Minnesota’s impeachment practices create disincentives that skew the adversarial process in the State’s favor.

This is the structural consequence of Spreigl: once other-acts evidence becomes normalized, the entire defense case becomes a minefield.

And like most forms of propensity reasoning in criminal law, the real-world burden falls heaviest on Black defendants and other marginalized communities, whose lives are more heavily policed, more heavily documented, and more easily mined for “other acts.”

The Core Problem: Spreigl Is Propensity Evidence Wearing a Thin Disguise

The justification for Spreigl has always rested on a legal fiction: that other-acts evidence is admitted not for propensity, but for some specific permitted purpose. But the distinction collapses under basic logic.

If the State introduces a prior domestic assault to prove “intent,” what is the jury really hearing?If the State introduces a prior drug sale to prove “knowledge” or “identity,” what inference is actually being activated?

The line between “intent” and “propensity” is not meaningful to a lay jury. It is barely meaningful even to lawyers. Minnesota courts know this; the original Spreigl opinion bluntly acknowledged that jurors may “give excessive weight” to a defendant’s prior wrongs and may convict, not because the State proved the present charge, but because the defendant “likely did such acts” in the past.

When a doctrine depends on jurors performing mental gymnastics human beings are not wired to perform, that doctrine is constitutionally defective. If the rule is built on a fiction—and that fiction routinely erodes constitutional protections—the rule must go.

Spreigl Evidence Punishes Defendants Who Go to Trial

One of the least discussed but most damaging consequences of Minnesota’s Spreigl doctrine is its role in creating and amplifying the trial penalty: the dramatic difference between what is offered in a plea and what happens after a conviction at trial.

Here’s how Spreigl supercharges the trial penalty:

1. Spreigl as bargaining chip: Prosecutors routinely threaten to introduce Spreigl evidence if the defendant insists on trial. That threat alone pressures defendants into taking pleas—even in weak or close cases. The message is unmistakable:

   “If you go to trial, we’ll tell the jury about every allegation we can scrape together.”

   
   

2. Spreigl as trial punishment:Once a defendant chooses trial, Spreigl becomes the State’s shortcut around evidentiary fairness. The defendant must now defend:

   • the charged conduct and

   • separate alleged acts the State never had to prove beyond a reasonable doubt.

     
     

3. Spreigl as conviction multiplier: Studies on propensity evidence show that even a single prior bad act can dramatically increase conviction rates. When Minnesota courts greenlight multiple Spreigl incidents, the trial becomes unwinnable—not because the State proved its case, but because it changed the case being tried.

Under any honest constitutional analysis, a regime that punishes the decision to go to trial is incompatible with due process and the Sixth Amendment. Spreigl is not neutral; it is a built-in penalty for demanding the trial the Constitution promises.

Why Minnesota Should Abandon or Radically Reform Spreigl

Minnesota is increasingly an outlier. Many jurisdictions have moved away from broad other-acts doctrines because they undermine fair-trial rights. Even in federal court, where Rule 404(b) governs “other-acts evidence,” judges tend to apply it more cautiously than Minnesota courts apply Spreigl. We are not more “principled”; we are more comfortable with shortcuts.

Legal scholars have called for reform for over a decade. Judges around the country have warned that other-acts evidence is among the most prejudicial categories of evidence in criminal law. The Minnesota Supreme Court’s own warnings from 1965 have proven prophetic. Yet the doctrine persists—expanded, routinized, and increasingly incompatible with modern constitutional jurisprudence.

At this point, Spreigl evidence operates like an unwritten constitutional amendment in Minnesota criminal trials: the presumption of innocence, the right to testify, and the right to present a defense all shrink the moment the State invokes “intent” or “identity.”

The time has come for Minnesota to acknowledge what its own caselaw has long known: Spreigl evidence is a constitutional liability.

Conclusion: Return to First Principles

A fair trial requires more than procedural formalities. It requires a system that:

• honors the presumption of innocence,

• protects a defendant’s right to speak,

• respects the right to call witnesses, and

• ensures that a jury’s verdict is based solely on evidence related to the charged crime.

  
  

Spreigl evidence erodes each of these principles. It smuggles propensity into the courtroom. It invites jurors to punish defendants for unrelated allegations. It chills defendants from testifying and presenting witnesses. It forces mini-trials on collateral matters. And it undermines the constitutional guarantee that every defendant is entitled to a fair trial based on what the State can prove now—not on who the State claims they were then.

Minnesota should retire the Spreigl doctrine. Until that happens, Minnesota’s criminal justice system will continue to punish defendants for exercising their constitutional rights.

The bottom line is: every defendant deserves better and the Constitution demands better. So Minnesota’s courts should require nothing less.