Fantasy role play and “ageplay” were at the heart of a Court of Appeals decision last week, after a man convicted of an Internet sex crime claimed his expert witness was not allowed to fully explain to the jury the dynamics of online interactions involving pretend personas.

A three-member appeals panel, in a decision issued on April 22, ultimately decided restricting the expert’s testimony was proper because his statements would not have spoken to a central element of the crime: whether the defendant believed he was communicating with someone underage.

However, Adam Mueller, an attorney for defendant Daniel Battigalli-Ansell, indicated he would appeal this decision to the Colorado Supreme Court, given that the precise issue at hand had never been adjudicated before.

“Those limitations denied our client his constitutional due process right to present a defense, and there is a reasonable probability the result would have been different if the jury had heard this important testimony,” Mueller said.

Battigalli-Ansell had used the online chat site Omegle to send instant messages with a person named “Brooke,” who was actually an investigator with the First Judicial District Attorney’s Office in Jefferson County. On its homepage, Omegle, which allows for text and video conversations, cautions users who are under 18 to obtain a parent or guardian’s permission, as “Predators have been known to use Omegle.” Nonetheless, the company advises that revealing one’s true identity is “not suggested” when using Omegle.

“Brooke” told Battigalli-Ansell she was 14 years old, and Battigalli-Ansell assumed a fake identity for himself in response. He asked “Brooke” whether she would have sex with him, and over the course of additional messages, “Brooke” gave him her phone number. The investigator sent a photograph of an 18-year-old intern at the prosecutor’s office to Battigalli-Ansell, and he replied with a photo of his genitals.

One month later, the same investigator, still under the pseudonym of “Brooke,” interacted with Battigalli-Ansell again. They similarly exchanged online chat messages, text messages, phone calls, and ultimately Battigalli-Ansell sent another genitalia photo.

A jury convicted Battigalli-Ansell of Internet sexual exploitation of a child, which required him to know the person with whom he communicated was under 15. Battigalli-Ansell had argued he believed “Brooke” was actually an adult who was simply role playing as a child. During his trial, the defense called upon a prominent marriage, family and sex therapist, Marty Klein, to explain fantasy-based erotic roleplay in chatrooms.

But on appeal, Battigalli-Ansell claimed the trial court had improperly limited the topics Klein could speak about.

Jefferson County prosecutors argued to District Court Judge Christie A. Bachmeyer that Klein should not be allowed to opine on the benign nature of fantasy role play and ageplay, studies showing role play is part of normal sexual interactions, and that fantasy role play does not implicate someone as a pedophile, among other topics.

Bachmeyer only permitted the expert to speak about the definition of fantasy role play and ageplay as applied to the Internet, determining that any other discourse “would be a needless waste of time, might create confusion and would not be helpful to the jury.”

Judges on the appellate panel appeared equally quizzical of both sides during oral arguments as they attempted to understand what Klein’s opinions could have contributed to the trial.

“The legislature had said this kind of conduct, sending a text of your sex organs and pretending to engage in this, is unlawful,” said Judge David J. Richman. “How is that opinion relevant, that ‘other people do it and I, Dr. Klein, think it’s normal?’ And the legislature said, ‘It’s unlawful. It’s not normal.’”

“Can we agree,” countered Judge Lino S. Lipinsky de Orlov, “that some adults use Omegle for fantasy ageplay? And that in the course of the ageplay, no one says, ‘I’m ageplaying,’ because that would break the spell? And if that’s right, why couldn’t an expert explain to a lay jury that adults engage in that type of communication through sites like Omegle?”

Trina K. Taylor, assistant attorney general, acknowledged that adults use Omegle for ageplay, but said general context was all the expert witness should be able to discuss. Norman Mueller, representing Batigalli-Ansell, argued instead that in the absence of an expert to interpret the literal transcript of the interaction, “the jury doesn’t understand why is ageplay a part of normal fantasy role play.”

The panel ultimately disagreed with Mueller’s statement, finding that Klein’s opinion about the transcripts being consistent with fantasy ageplay “addressed more than the general characteristics of people who engage in fantasy age role-play.”

Klein’s planned testimony would have been “irrelevant to the sole issue at trial — whether Battigalli-Ansell believed he was communicating with a person under fifteen years of age or someone older,” wrote Lipinsky in the court’s decision.

Battigalli-Ansell’s attorneys said he is currently serving a sentence of 10 years to life on probation. Klein declined to comment on the court’s decision or his intended testimony, but his website includes a post from December 2009 describing another trial in Colorado in which he testified, where a man conversed online with an underage persona whom the defendant allegedly believed was ageplaying.

“Was he really trolling for a kid to have sex with? I don’t know — I never spoke to the guy, certainly never evaluated him clinically,” Klein wrote about the defendant in that instance. “But the burden was not on him to prove he wasn’t. Since the State had taken the trouble to arrest him, humiliate him, accuse him, and destroy his life, the burden was on the State to prove, beyond a reasonable doubt, that his behavior was calculated and dangerous.”

The case is People v. Battigalli-Ansell.