A gunman who killed his surgeon and three other people at a Tulsa medical office blamed the doctor for his continuing pain after a recent back operation and bought an AR-style rifle just hours before the rampage, police said Thursday. https://www.fox4news.com/news/tulsa-hospital-shooting-suspect-purchased-ar-style-rifle-hours-police Subscribe to FOX 4: https://www.youtube.com/fox4news?sub_confirmation=1 Watch FOX 4 Live: https://www.fox4news.com/live Dallas news, weather, sports and traffic from KDFW FOX 4, serving Dallas-Fort Worth, North Texas and the state of Texas. Download the FOX 4 News app: https://fox4news.onelink.me/TXYK?pid=social&c=youtube&af_web_dp=https%3A%2F%2Fwww.fox4news.com%2Fapps Download the FOX 4 WAPP: https://www.fox4news.com/apps Follow FOX 4 on Facebook: https://www.facebook.com/Fox4DFW/ Follow FOX 4 on Twitter: https://twitter.com/FOX4 Follow FOX 4 on Instagram: https://www.instagram.com/fox4news/ Subscribe to the FOX 4 newsletter: https://www.fox4news.com/newsletters