https://www.westword.com/news/matthew-riehls-new-years-eve-shooting-new-details-10550299
https://abcnews.go.com/US/colorado-officers-describe-happened-horrific-ambush-style-attack/story?id=55102757
https://www.denverpost.com/2018/01/02/douglas-county-shooting-matthew-riehl-bipolar-ptsd/#:~:text=Matthew%20Riehl%2C%20the%20man%20who%20shot%20and%20killed,in%20the%20weeks%20leading%20up%20to%20the%20shooting.
https://www.cbsnews.com/news/report-matthew-riehl-gunman-in-deadly-colorado-deputy-attack-fled-mental-ward-in-2014/
https://www.cbsnews.com/news/colorado-shooting-concern-over-matthew-riehls-mental-state-flagged-a-month-ago/
https://taskandpurpose.com/news/colorado-shooter-matthew-riehl-va-hospital/