Tenth Circuit upholds Colorado sex-abuse conviction after expert notice fight

For criminal defendants, expert testimony can make a case feel like a battle over which side gets to tell its story first. In the Tenth Circuit’s United States v. Crow, that mattered because the fight centered on whether the jury would hear a sleep-disorder explanation before the government had a chance to answer it. The court said prosecutors did not have to give advance notice of rebuttal testimony when it was responding to defense material the defendant himself had not disclosed.

The appeal came out of the District of Colorado and involved sexual-abuse allegations at a military base. Mitchel Crow admitted having sex with a girl who lived with him, but he said he had been asleep and had not knowingly done it. His expert pointed to sexsomnia, a sleep disorder that can lead to sexual activity during sleep.

Where the notice fight broke

The government responded with its own expert, who rejected the sleep-disorder explanation. The sharpest dispute came when the defense expert later strayed into an opinion that had not been included in the written disclosure: he said he did not believe Crow was malingering, meaning faking symptoms or an illness. That shift mattered because the government’s rebuttal was aimed at a defense theory that had surfaced at trial, not one that had been properly turned over ahead of time.

The panel said that distinction controlled the notice question under Federal Rule of Criminal Procedure 16. If the defense does not disclose the evidence in the first place, the government does not have to preview a rebuttal witness just because that witness will answer it in court.

What trial lawyers take from it

The ruling does not wipe out expert-disclosure rules. It draws a narrower line: advance notice is tied to rebuttal of defense testimony that was actually disclosed on time. When the defense introduces a new expert theory at trial, prosecutors get more room to respond without a separate warning shot.

That leaves the practical burden where criminal trials often put it, on preparation. Defense lawyers who want to use an expert to shape a jury’s view of intent, memory, sleep, or diagnosis now have a clearer reason to disclose the theory early. Otherwise, they may give the other side exactly the opening they were trying to avoid.