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. 

Here is what we know so far about the victims of the shooting. 

Dr. Preston J. Phillips, M.D.

Dr. Preston J. Phillips, an orthopedic surgeon and section chief at the Warren Clinic in Tulsa, was described by police as the intended target of Wednesday’s shooting.

Phillips, 59, graduated from Harvard Medical School in Boston and completed his residency at Yale New Haven Hospital in Connecticut.  

On Facebook, a man named Phil Brewer described knowing Phillips during residency: 

“We shared a love of jazz and frequently went to a small jazz club in New Haven to listen to live music. Preston introduced me to the music of Marion Meadows, a New Haven native. He was an impressive man, both physically and intellectually. He was selected as a White House fellow before going to medical school. He was one of the very few black orthopedic surgeons in the country.”  

WHAT WE KNOW:Police identify victims, gunman in Tulsa medical center shooting

Phillips’ neighbors, Paul and Patti Bernius, remembered him as “the best type of neighbor you would want to live in your neighborhood.”

“He was just the most incredible man,” Paul Bernius said. “In character, in professionalism, in everything he did – just 10s across the board. Think high, and then think higher – that’s my view of him.”

Phillips served on the board of directors for Tulsa’s John Hope Franklin Center for Reconciliation in the Greenwood District, which works within the community to change the nature of Tulsa’s relationship with its violent past of racial violence surrounding the Tulsa Race Massacre.  

He was also a member of the Oklahoma State Medical Association, and frequently volunteered with the Tulsa County Medical Society’s free clinic, Project TCMS, according to an association spokesperson.