The 49-year-old S.W.A.T. star announced the sad news in a series of Instagram videos on Wednesday, and shared that she died on Feb. 8. She was 76 years old. In the emotional videos, Moore fights back tears, explaining that he owes all of his success to her.
"This is real life," he says. "Your baby boy is OK, but I'm hurt real bad. It's not a game, it's not a joke, I'm hurting real bad. ... She's gone. This is my whole life, everything I've ever known."
Moore then held up a picture of his late mother.
"I stay stunned," he says. "I am heartbroken. Marylin Joan Wilson-Moore was my partner in crime ... my Bonnie to my Clyde. Everything I've ever known, everything I've ever worked hard for, 'Mama, here comes that man.' I don't know life without this woman."
"I don't know what to do but I will figure it out because that's what she would want," he continues about dealing with his intense grief. "But everything I am, everything I've accomplished, is because of this amazing woman. My mother is gone, she ain't here no more, but she's here. I've been quiet because I've been crying a lot. I've been yelling and screaming, 'No, no, no, no, no.' ... We had plans, we were almost there. She was tired."
Although Moore didn't specify how his mother died, he did mention that she suffered from heart issues and multiple sclerosis.
"She's gone and it's killing me," he says. "I'm down. I have to figure out the next chapter without my mom. ... I am gonna stand up and I am going to continue to chase my dreams and be somebody ... because that's the boy she raised. I'm gonna miss my mama for the rest of my life."
The former Criminal Minds star ended his emotional message to fans by playing Joe Cocker's "You Are So Beautiful" on his phone, while holding up his mom's picture and a wine glass.
In a follow-up Instagram post, Moore shared throwback pictures and videos of him and his mom set to Celine Dion's "Because You Loved Me."
"My Mama always said 'I was at the front of the line when God was handing out sons' .... and I always said 'Mama, you know I cut the line to get to you!'" he captioned the post. "❤️ I love you mama ❤️."
"I was in denial," Moore told ET at the time of his mother's diagnosis. "I was like, 'Ma, take some aspirin. Get a good night's sleep. It'll go away.' I didn't want to accept it. But then I saw her start to, you know, she wasn't able to do a lot of things that she normally could do… It started to hit home."
"I'm raised by a single mom and didn't have Pops around for the most part of my life," he continued. "And she, by any means necessary, gave me the best opportunities that she knew how to give me. ... When you're a kid, your parents are invincible. I always thought of her as my super mom and MS is her kryptonite. She's cracked a little bit, but I always say that she'll never break."
"Without Kristoff embracing me, teaching me, rooting for me, always believing in me, I don't have this career," he told ET backstage. "He was a true friend. He was my TV brother, but it felt so genuine and real in my heart. He's my real brother in real life and he always will be."