Content warning: This story discusses suicide.
According to the report, Miller was found in the bathtub of his home and was pronounced dead at the scene. The document also stated that letters specifying intent were also recovered. Additionally, it was confirmed he suffered from bipolar disorder and depression.
Miller's manager previously shared the Emmy winner died on Sept. 15 in Austin, Texas, just two days before his 44th birthday. After his passing, his mother Patricia Miller spoke out about the tragic loss, thanking fans, friends and colleagues for the "overwhelming amount of love" their family received.
"He fought a long hard valiant battle with bipolar depression for years," she said in a Sept. 18 statement shared to social media by the actor's publicist. "He did everything he could to control the disease. He loved his family, his friends and his fans but in the end the disease won the fight and he surrendered his life."
She continued, "We all loved him so much and are desperately trying to deal with our loss."
The soap opera star was also honored with touching tributes shared by fellow costars, including Chrishell Stause, who worked alongside Miller on All My Children.
"Too many feelings," she wrote in a social post at the time, "but you are gone way too soon and I'm so happy I got to work with you all those years, but also call you a friend. I hope you are at peace now."
Miller's Ringer costar Sarah Michelle Geller also reflected on his lasting legacy, noting in an Instagram Story post, "It was an honor to work with you but more of an honor to know you."