McDowell: Reverse 404(b), Rule 412, and the Right to Present a Defense

An enlisted panel convicted McDowell of seven specifications of sexual abuse of a child and sentenced him to thirty-six years of confinement, a dishonorable discharge, forfeiture of all pay and allowances, and reduction to E-1. ACCA summarily affirmed the findings and sentence in December 2025 and later denied reconsideration.

The defense theory at trial was that someone else committed the offenses. The SODDI defense. Specifically, the defense identified the alleged victim's older half-brother, Caleb, as the alternative perpetrator.

After investigators seized the alleged victim's blanket, DNA testing did not find any from the appellant. Instead, testing identified semen from Caleb, not McDowell. According to the defense, the blanket belonged to the alleged victim, she slept with it every night, and it was found on her bed.

The defense sought to introduce evidence concerning Caleb's prior behavior, including violence and sexual behavior, as part of its effort to explain why the alleged victim might have accused McDowell rather than Caleb. Caleb died by suicide shortly before trial and left a farewell message expressing regret that he had "done a lot of bad things."

The military judge excluded significant portions of the evidence. That produced the two questions McDowell now asks CAAF to review.

I. Whether the military judge abused his discretion in excluding "reverse 404(b)" evidence.

II. Whether the military judge abused his discretion in excluding DNA evidence under Military Rule of Evidence 412.

Does the Defense Get the Same Rule With a Different Balance?

This case gives CAAF the chance to answer: how does Mil. R. Evid. 404(b) operate when the defense, rather than the prosecution, offers evidence of another person's acts? Other federal courts have already written on the question in some fashion.

There is a constitutional principle underlying both issues. The right to present defense evidence tending to rebut an element of the government's proof; the identity of the perpetrator, is a fundamental constitutional right. United States v. Valenzuela-Bernal, 458 U.S. 858 (1982); Chambers v. Mississippi, 410 U.S. 284 (1973); Webb v. Texas, 409 U.S. 95 (1972); United States v. Woolheater, 40 M.J. 170 (C.M.A. 1994); see also Holmes v. South Carolina, 547 U.S. 319 (2006); United States v. Crosby, 75 F.3d 1343 (9th Cir. 1996).

“The right to present defense evidence tending to rebut an element of proof such as the identity of the perpetrator is a fundamental Constitutional right.” 40 M.J. at 173. McDowell's petition invokes that principle in arguing that a complete defense includes the opportunity to show that someone other than the accused committed the crime.

Woolheater puts the point directly.

In Posey v. State, the Florida Third District Court of Appeal the court was applying Florida 90.404(2)(a) and wrote:

Where typically the prosecution invokes the Williams rule in order to introduce evidence of the defendant’s similar, relevant other crimes, this Court since Moreno has recognized a defendant’s right to offer similar-crime evidence to “show his innocence by proof of the guilt of another.” Id. at 1225-26. This inversion of the role of the Williams rule for the defendant’s benefit, so that the defendant may introduce evidence to establish a reasonable doubt of his or her guilt, is known as the “reverse Williams rule.” Rivera v. State, 561 So. 2d 536, 539 (Fla. 1990).

That does not make every item of alternative-perpetrator evidence admissible. Ordinary evidentiary rules still apply. But Holmes is important. A court may not arbitrarily exclude defense evidence based on an assessment of the strength of the prosecution's case rather than the probative value and potential adverse effects of the defense evidence itself. 547 U.S. 319, 324-30. That distinction seems to fit McDowell. 

Ordinarily, Rule 404(b) appears when the prosecution offers an accused's other acts for a non-propensity purpose. But federal courts have also recognized what has become known as "reverse 404(b)." Instead of using other-act evidence to incriminate the accused, the defense uses another person's acts to exculpate the accused.

Under the federal and military rule one non-propensity purpose is to establish identity. Is that limited to the identity of the accused or does it include the culprit. McDowell asks, why can't it be identity of the culprit. Mil. R. Evid. 404(b)(2).

A significant case is United States v. Stevens, 935 F.2d 1380 (3d Cir. 1991).  Stevens reasoned that the usual concern about unfair prejudice operates differently when the accused offers evidence concerning a third party. There is no danger that a factfinder will convict the accused because of his bad character. Consequently, the Third Circuit held that reverse-404(b) evidence may be admitted when it tends to negate the accused's guilt and survives ordinary Rule 403 balancing.

McDowell asks CAAF to decide whether that doctrine applies in courts-martial and whether defense-proffered 404(b) evidence receives the more permissive treatment recognized by several federal circuits.

The issue matters because the defense says it was not offering Caleb's acts simply to prove, "Caleb was a bad person, therefore Caleb committed the offenses." Rather, it offered at least some of that evidence to explain the alleged victim's state of mind and a possible motive to accuse McDowell rather than a half-brother she allegedly feared. Trial defense counsel expressly told the military judge that the defense was trying to show the environment in which the alleged victim lived and why she might have had a reason not to identify Caleb.

It is generally accepted that a piece of evidence that is objectionable on two or three grounds, may be admitted for a fourth reason; admitted for that limited purpose, and accompanied by a limiting instruction? Mil. R. Evid. 105. The broader question is also interesting. Mil. R. Evid. 404(b) says evidence of another act by a person may be admissible for a non-propensity purpose. It does not say the rule belongs exclusively to the prosecution. And CAAF has long described 404(b) as a rule of inclusion rather than exclusion.

The Ninth and several states have examples of pattern jury instructions when there is SODDI evidence that could be tailored. See below for New Jersey, as an example.

That distinction may prove important. The prohibition against propensity evidence remains. The question is whether the military judge treated a permissible inference about motive or state of mind as though the defense were simply offering forbidden propensity evidence.

The second issue may be even more interesting.

Mil. R. Evid. 412 generally excludes evidence offered to prove an alleged victim's other sexual behavior or sexual predisposition. The obvious question in McDowell is whether DNA showing another person's semen on the alleged victim's blanket necessarily constitutes evidence of the alleged victim's sexual behavior at all. How can it. She's still a victim, but allegedly of a different person than the accused. Isn't it generally considered that being a victim is not evidence of sexual behavior?

McDowell's point is straightforward: the evidence establishes something about Caleb. His semen was on the blanket. That fact, standing alone, does not establish that the alleged victim engaged in any sexual behavior.

The petition relies on United States v. Erikson, 76 M.J. 231 (C.A.A.F. 2017), where CAAF rejected an expansive conception of Rule 412, observing that the sexual assault of a victim does not necessarily concern that victim's "sexual behavior" or "sexual predisposition." McDowell argues that the same principle applies here: Caleb's ejaculation on the blanket does not itself describe the alleged victim's sexual conduct.

That raises a potentially important boundary question for Rule 412. Does the rule apply because evidence has a sexual character or involves semen? Or must the evidence actually concern sexual behavior or predisposition of the alleged victim?

Even if Rule 412 applies, subsection (b)(3) requires admission when exclusion would violate the accused's constitutional rights. CAAF's cases ask whether the evidence is relevant, material, and favorable to the defense.

Here, the DNA evidence did not come from a speculative defense fishing expedition. Investigators collected the blanket and tested it. According to the defense, the government expected the forensic examination to corroborate the alleged victim's account. The result instead identified Caleb. The military judge nevertheless excluded the evidence, reasoning in part that because the alleged victim identified McDowell rather than Caleb, the connection between Caleb's DNA and the charged offenses depended upon attenuated suppositions. He also expressed concern about the "CSI effect" the DNA evidence might have on the members. Which completely misses the point of the SODDI defense. Interesting comment about the CSI effect of defense evidence, but not the government's.

Within the question lurks a boundary question. When is the military judge invading the province of the factfinder.

McDowell presents two separate evidentiary issues, they converge on a single constitutional concern.

The Supreme Court has repeatedly recognized that an accused must have a meaningful opportunity to present a complete defense. CAAF likewise has recognized that the right includes presenting evidence tending to show that someone other than the accused committed the offense. McDowell invokes that principle directly.

The case does not merely ask whether one item of DNA evidence or several pieces of other-act evidence should have come in. It asks how ordinary exclusionary rules operate when their application prevents an accused from presenting evidence identifying a specific alternative perpetrator.

The reverse-404(b) issue asks whether evidentiary rules developed largely to protect defendants from prejudicial character evidence should operate differently when the defendant uses them as a shield.

The Rule 412 issue asks whether the rape-shield rule reaches physical evidence of another person's sexual conduct when the defense does not offer that evidence to prove the alleged victim's sexual behavior.

How much evidentiary filtering may a military judge perform before the judge has effectively prevented the members from hearing the defense?

The Evidence May Matter More Together Than Apart. The two issues should not necessarily be viewed in isolation.

The military judge considered whether particular pieces of evidence independently established a sufficiently strong connection between Caleb and the charged offenses. But the defense theory depended on the evidence working together.

The DNA established an objective physical connection: Caleb's semen was found on the alleged victim's blanket, which the defense says was recovered from her bed. The other-act evidence supplied context for why that fact might matter. According to the defense theory, Caleb's conduct toward the alleged victim and his history of violence helped explain both why he was a plausible alternative perpetrator and why the alleged victim might have had a reason not to identify him.

The relationship runs in both directions. Standing alone, evidence of Caleb's troubling conduct might invite the objection that the defense was merely inviting propensity reasoning. But the DNA gives the defense something more than a theory based on Caleb's character. Conversely, standing alone, Caleb's semen on a blanket might permit innocent explanations and appear too attenuated from the charged offenses. (Of course, had McDowell's DNA been found instead, should we assume the government would be arguing there is no innocent explanation?) The other evidence provides context from which the defense says the members could evaluate competing explanations for why it was there.

Neither piece of evidence necessarily proves the defense theory. The more interesting question is whether a court may assess each piece in isolation when relevance depends in part on how the evidence fits together.

That concern has particular force here because the military judge reasoned that getting from Caleb's DNA on the blanket to a fact of consequence required a "series of attenuated suppositions unsupported by evidence." But some of the evidence that might have supplied the missing links was itself excluded.

That creates something of an evidentiary loop. The DNA can be characterized as too attenuated without the contextual evidence. The contextual evidence can be characterized as propensity evidence or speculation without the DNA. Exclude each because the other is absent, and the members never see the combination on which the third-party-culpability defense actually rests.