A man who blamed his surgeon for ongoing pain after a recent back surgery bought an AR-style rifle hours before opening fire at a Tulsa medical office on Wednesday, killing four before fatally shooting himself, police said Thursday. Three of the four victims were employees of the Saint Francis Health System. "The three best people in the entire world that are the most committed to doing what they do every day and taking care of others," said CEO Dr. Cliff Robertson on Thursday. Click the link in our bio to learn more on what we know so far about the victims of the shooting.