A cardiac surgeon at Brigham and Women's Hospital died of gunshot wounds on Tuesday evening, hours after he was shot by a man who opened fire inside the medical center and later killed himself, officials said.

Michael Davidson, MD, the hospital's director of endovascular cardiac surgery, died as a result of the morning shooting that occurred at the Shapiro Cardiovascular Center, the hospital said in a statement late on Tuesday.

The gunman, identified as Stephen Pasceri, 55, of Millbury, Mass., then shot and killed himself. Mr. Pasceri, whose mother recently died after having surgery at the prestigious hospital, asked for Dr. Davidson by name, police said.

"There was a particular reason he targeted this doctor," said Police Commissioner William B. Evans, adding that officials are investigating possible motives.

Dr. Davidson was shot in a foyer between the waiting area and the examining area on the second floor of the hospital's cardiovascular center, which is across the street from the hospital's main entrance. He was rushed to the hospital's ER. Police conducted a room-by-room search on the second floor and found the suspect's body in an exam room, a gun lying nearby.

Staff, patients and family members were trapped inside the building for about 45 minutes after the shooting, a witness told the Boston Globe. Panic ensued when police rushed into the cardiovascular center with guns drawn, shouting, "Get down!" or "Get back," according to a witness, and people began screaming and running toward the glass-enclosed walkway that connects the cardiovascular center to the other hospital buildings.

In a tweet sent out early Tuesday afternoon, the hospital said the situation was under control and that hospital operations were back to normal.

Jim Burger