EL PASO COUNTY, Colo. (KRDO) -- A former Monument Academy teacher accused of stabbing and killing one person and critically injuring multiple others in October 2025 pleads not guilty. 33-year-old Matthew Regnier was arrested and charged with first-degree murder, two counts of attempted first-degree murder, two counts of first-degree assault, and one count of child abuse. According to the Colorado Springs Police Department, on Oct. 31, 2025, they…