Thursday marks one year since a man shot and killed four people before turning the gun on himself at a medical center in Tulsa.Get the latest news stories of interest by clicking here.Shortly before 5 p.m. on June 1, 2022, a gunman charged into the second floor of the Natalie Building at St. Francis Hospital, opening fire and killing four victims. Police said the suspect, Michael Louis, then died of a self-inflicted gunshot wound.Dr. Preston Phillips, Dr. Stephanie Husen, Amanda Glenn, and William Love were killed in the mass shooting.Tulsa police chief said shortly after the shooting that Louis underwent surgery performed by Phillips in mid-May and complained about continued pain after being released from the hospital. Louis called Phillips' office several times over the coming weeks and met with him for additional help. >> Download the KOCO 5 AppLouis bought a semi-automatic handgun on May 29 and an AR-15-style rifle the day of the shooting. Police said they found a letter on Louis making it clear that he wanted to kill Phillips and anyone who got in his way and that he blamed Phillips for causing the pain following the back surgery. Top Headlines Urgent search underway for man accused of being involved in shooting with Okmulgee police Suspect in custody after deadly shooting at Oklahoma City motel Choctaw neighborhood at standstill after tactical units respond to possible high-risk situation Oklahoma man hospitalized after attacked by Africanized killer bees Oklahoma breweries notice ‘sober curious’ trend gaining traction across country