In the opening seconds of the forthcoming Investigation Discovery documentary series Love and Hate Crime, convicted murderer Joshua Vallum looks directly at the camera and says, “I have to live with the fact that I killed Mercedes and she’s in hell.”

But as the next hour unfolds, it becomes clear that if anyone is in hell, it is certainly not transgender teenager Mercedes Williamson, whose decomposing body was found by police on Vallum’s father’s property in June 2015.

Rather, it is Vallum himself who lives inside a hell of his own creation.

By pointing the camera at the imprisoned Vallum and allowing him to speak at length about his relationship with Williamson, director Ben Steele—who previously directed the excellent HBO documentary Hunted: The War Against Gays in Russia—allows the paradoxes inside the 29-year-old’s mind to unravel onscreen, slowly and horrifyingly.

“We were trying to go inside his head and understand his motivations—to understand the dilemma that, ultimately, he kills Mercedes because he loves her but he hates her and he hates himself for loving her,” Steele told The Daily Beast.

Last year, Vallum’s brutal 2015 killing of Williamson in Mississippi became the first ever murder of a transgender person to be successfully prosecuted under the federal Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act.

The facts of the case, according to a May 2017 press release from the U.S. Justice Department announcing Vallum’s sentencing, are as follows: Vallum and Williamson had a “consensual sexual relationship” and Vallum, of his own admission, “knew Williamson was transgender”—a fact that he tried to hide from almost everyone he knew, including fellow members of the Latin Kings gang to which he belonged.

“Vallum admitted, as part of his guilty plea, that on May 28, 2015, he decided to kill Williamson after learning that a friend had discovered Williamson was transgender,” the press release notes. “Vallum believed he would be in danger if other Latin Kings members found out that he had engaged in a consensual sexual relationship with a transgender woman.”

Vallum then “lure[d] Williamson into his car” and drove her to his father’s house in Mississippi where he “used a stun gun to electrically shock Williamson in the chest, repeatedly stabbed [her], and struck [her] with a hammer until she died.”

But that is not the story Vallum tells viewers in the haunting hour of Love and Hate Crime, which was filmed before the young man would go on to plead guilty to a hate crime in December 2016.

The Vallum of the documentary claims that he didn’t know Williamson was transgender until the day he killed her, and that after discovering she had a penis, he “snapped” and began to stab her.

“I don’t know why I didn’t stop,” he claims.

The Vallum of the plea hearing, however, apparently said that he knew Williamson was transgender all along—and that the murder was pre-planned.

“What we see in the character, and not just the character but the reality of Josh is someone who is wrestling with diverse notions of himself,” Steele told The Daily Beast of his approach to his unreliable subject. “And it’s up to the audience, it’s up to the viewer, to come to the conclusion whether or not he’s fully understood and come to terms with himself or not.”

The rationalization that Vallum deploys in the film—that he only killed Williamson because he unexpectedly found out she was transgender during the course of their relationship—is known as the “trans panic” defense, and it is used to try to excuse or mitigate the seriousness of murdering a transgender person. As The Daily Beast’s Jay Michaelson recently observed, it is only illegal in two states: California and Illinois.

As the National LGBT Bar Association notes on its website, the killers of gay college student Matthew Shepard tried to cite the common homophobic equivalent of the “trans panic” defense: the “gay panic” defense. Shepard is now one of the namesakes of the legislation under which Vallum was prosecuted.

But rather than debunk the killer’s story through overt narration, or challenge his story at every turn, Steele frames the story through Vallum’s perspective and then allows contextualizing information about the murder to emerge slowly through secondary interviews with a police officer, with Williamson’s friend Destiny Allen, and with a local journalist who investigated the case.

Williamson’s transgender status is only revealed partway through the documentary.

Those are risky filmmaking choices in a society already disinclined to believe transgender people and all too ready to sympathize with their abusers.

But if some viewers find themselves initially swayed by Vallum’s account—and in a deeply transphobic culture, the “trans panic” defense has indeed proven persuasive in the past—then Steele says that’s by design.

“I think there will be people in the audience who initially will be quite strongly sympathetic to Josh and will then be forced to confront during the film some of the ramifications of initially being sympathetic to him,” he explained, adding that this structure “[enables] the audience, through the story, to examine their own prejudices.”

Ultimately, Steele maintains, Vallum’s actions aren’t just the result of individual choices, they are also a reflection of the value systems in which he was raised: the homophobic and transphobic culture of the Latin Kings gang, the Christianity of the Deep South, and the anti-LGBT sentiment that can be found across the United States.

The chilling picture that Steele paints between the lines of his film is of a young man who could not reconcile his internal paradoxes, and sought out a violent solution.

“I think that Mercedes’ life was cut short and she was brutally murdered because of decisions that Josh took, because of choices that Josh took,” Steele said. “But Josh is also a product of his environment, he’s a member of a community, and he’s a member of a family—and I think that has had great significance in how he sees himself. The murder is not just an act of violence against Mercedes; in many ways, it’s an act of violence against himself.”

But it’s an act of violence that only cost one person her life.

Love and Hate Crime premieres on Feb. 25 on Investigation Discovery.