Shortly after 11 a.m. Tuesday, a man walked into Brigham and Women's Hospital, asked to speak with Dr. Michael J. Davidson, and, when the cardiovascular surgeon stepped into an exam room to speak, fired two shots. Twelve hours later, police and hospital administrators announced that Davidson, a father of three whose wife is a plastic surgeon, had died after he was rushed to the emergency room and underwent surgery. A preliminary investigation suggested his assailant, identified as Stephen Pasceri, 55, of Millbury, "had some issue" with prior medical treatment of his mother at the hospital, said Superintendent Robert Merner, head of the Bureau of Investigative Services. Marguerite E. Pasceri died Nov. 15.
