The cause of death for C.J. Harris has been confirmed.
The Walker County coroner had previously told E! News that Harris' death appeared "natural" with no signs of evidence showing foul play.
Harris appeared on American Idol's 13th season in 2014, wowing the judges—who at the time were Harry Connick Jr., Jennifer Lopez and Keith Urban—with his rendition of Allman Brothers Band's "Soulshine" during Salt Lake City auditions. His talents took him to the top 10, with his notable performances including covers of The Marshall Tucker Band's "Can't You See" and John Mayer's "Gravity."
After news of his passing, members of the American Idol family paid tribute to the singer, who finished in sixth place that season.
"C.J. Harris was an incredible talent, and the news of his passing deeply saddens us," American Idol tweeted on Jan. 16. "He will be truly missed."
Season 13 winner Caleb Johnson said he formed "so many amazing memories and experiences" with Harris, adding, "Life is so fragile!"
"This hurts so much," Johnson wrote on Instagram Jan. 16. "CJ was my roommate on @americanidol during Hollywood week and then lived right next door to me and @realalexpreston during the live shows. We instantly became friends and formed a brotherhood pack," alongside contestants Alex Preston and Sam Woolf.
Jess Meuse, who finished in fourth place, said she felt "completely shocked."
"Your talent and smile will be missed, and the world is definitely a darker and eerily quieter place without you in it," she said on Instagram Jan. 16. "I'll miss your random phone calls asking for life advice and talking about the music world. When you go through something like Idol together, it brings everyone involved together like a big, weird, dysfunctional family."
Before landing a spot in American Idol's 13th season, Harris auditioned in 2010 but "never made it past the first round," he told the Hollywood Reporter in 2014. He also applied for The X-Factor and The Voice, though he said he "never got through, and it hurt me."
Nevertheless, Harris was passionate about pursuing his dream.
"I was always on the internet, trying to find a break, looking for which producers I could send my stuff to," he said. "I searched for American Idol and I saw they were doing the bus tour and they were going to be 30 minutes down the road from me. I said, ‘You know what? I'm going to give it another chance. I've gotten so much better, my voice has matured and my playing has gotten so much better."