Baltimore ? A man who became distraught as he was being briefed on his mother’s condition by a surgeon at Johns Hopkins Hospital pulled a gun and shot and wounded the doctor Thursday, then killed his mother and himself in her room at the world-famous medical center, police said.

The gunman, 50-year-old Paul Warren Pardus, had been listening to the surgeon around midday when he “became emotionally distraught and reacted … and was overwhelmed by the news of his mother’s condition,” Police Commissioner Frederick H. Bealefeld III said.

Pardus pulled a semiautomatic gun from his waistband and shot the doctor once in the abdomen, the commissioner said. The doctor is expected to survive.

Pardus then holed up in the room in a more than two-hour standoff. When officers made their way in, they found Pardus and his mother, 84-year-old Jean Davis, shot to death, he on the floor, she in her bed.

Pardus’ brother, 59-year-old Alvin Gibson of Remington, Va., said their mother suffered from arthritis and rheumatism and had surgery last week, but it didn’t help her.