A man pleaded guilty Monday to fatally stabbing his mother in their Castle Rock home in 2022. Matthew Buchanan, 34, pleaded guilty to second-degree murder, attempted first-degree murder, and attempted aggravated cruelty to animals. Other charges were dismissed as part of the plea agreement. Read more: https://www.9news.com/article/news/crime/man-pleads-guilty-fatally-stabbing-mom-castle-rock/73-a40b0f50-4e6f-403a-b369-9676c714daf0 ----- More local videos here: https://youtube.com/@9news Subscribe to NEXT: https://youtube.com/@Nexton9NEWS Stay connected: 9NEWS Website: https://www.9news.com/ Facebook: https://www.facebook.com/ilike9news Twitter: https://twitter.com/9NEWS Instagram: https://www.instagram.com/9newsdenver/ Download the 9NEWS App: https://www.9news.com/appredirect/ Sign up for the 9NEWSLETTER: https://www.9news.com/email 9NEWS (KUSA) is located in Denver, Colorado.