The Shasta County Sheriff's Office (SCSO) received a Cybertip from the National Center for Missing and Exploited Children (NCMEC) on March 10, 2026, suspecting child sexual abuse material distribution. Holmes was arrested at his home after an arrest warrant was issued on June 11, 2026. Detectives found additional evidence, including high-capacity firearm magazines and illegal assault weapons, as well as evidence of animal abuse.