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, is described by police as the intended target of Wednesday’s shooting.

Phillips 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 describes 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 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.  

“Dr. Phillips was the consummate gentleman. He was – he is a man that we should all strive to emulate,” Robertson said. 

“He is one of those doctors that was cut from the cloth of four decades ago in terms of how he felt about people and how he felt about his calling, so not only is it a shock, it is the ultimate loss for Saint Francis and for Tulsa.”

Dr. Stephanie Husen, D.O.

Tulsa shooting victim Dr. Stephanie Husen, D.O.

Dr. Stephanie Husen, a sports and internal medicine specialist with the Warren Clinic in Tulsa, graduated from the Oklahoma State University-Center for Health Services medical school in 2000 and completed her residency at Greenville Memorial Hospital in South Carolina.  

An Oklahoma native, Husen’s Facebook page shows she is from Ponca City. 

Amanda Glenn

Amanda Glenn was a receptionist working in a supervisory role for the offices at the medical clinic, according to Robertson.

According to her LinkedIn, Glenn had been with the Saint Francis Health System for nearly five years. Previously, Glenn was a registered medical assistant. 

A wife and the mother of two teenaged sons, Glenn was a fan of University of Oklahoma football and St. Louis Cardinals baseball, according to her Facebook.

In a post to Facebook, her brother, Jim Massengill wrote:

“I haven’t really came up with the words yet… I honestly have no idea what to say because I’ve been hysterically crying since I found out.