Our newest television addiction Love & Hate Crime is set to premiere on Investigation Discovery next month, and the true crime docu-series will begin with the disturbing murder of transgender teen Mercedes Williamson.

In a trailer for the upcoming episode, airing Feb. 25 on the cable network, Josh Vallum reveals how he regrets killing his then-girlfriend Mercedes after discovering she was born a man. "If there is anything in this world that I could take back, it would be that I would give Mercedes her life back," he says into the camera. "I would actually give my life in exchange for her life because the guilt that I'm living with is so horrible, it's not worth it."

He continued, "I know that I'm secure in my relationship with God but I don't know if Mercedes was secure, so I have to live with the fact that I killed Mercedes and she's in hell." Josh, who is born-again, was a Latin Kings gang member when he murdered Mercedes, 17, in May 2015. He pled guilty to murder, admitting to stabbing and beating her to death with a hammer.

At the time, he claimed the shock of finding out that she was transgender made him lose control and kill her. He also feared his gang would find out about the "homosexual" relationship, which is strictly prohibited. Last year, he became the first person to be sentenced on federal hate crime charges for killing a transgender person, according to Deadline.

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In her 2015 ESPY Awards speech, Caitlyn Jenner mentioned Mercedes and her gruesome death. "All across this country, right now, all across the world, at this very moment, there are young people coming to terms with being transgender. They’re learning that they are different and they are trying to figure out how to handle that, on top of every other problem that a teenager has," the LGBTQ advocate said. "Just last month, the body of 17-year-old Mercedes Williamson, a transgender young woman of color, was found in a field in Mississippi stabbed to death. I also want to tell you about Sam Taub, a 15-year-old transgender young man from Bloomfield, Michigan."

She continued, "In early April, Sam took his own life. Now, Sam’s story haunts me in particular because his death came just a few days before ABC aired my interview with Diane Sawyer. Every time something like this happens, people wonder, ‘Could it have been different, if spotlighting this issue with more attention could have changed the way things happen?’ We’ll never know."

Love & Hate Crime premieres Sunday, Feb. 25 at 8 p.m. EST on Investigation Discovery.