They are warning the public that the surgeon, Dr. Timothy Jorden, a former Army Special Forces weapons expert, may be armed and dangerous.
Police say 33-year-old Jacqueline Wisniewski was shot four times Wednesday morning in a stairwell at a building on the Erie County Medical Center. The shooting led to a lockdown that last more than four hours.
Police, including SWAT team members, later converged on Jorden's suburban home. By Wednesday night, they said the house was empty and they began leaving the property.
They declined to say what relationship Jorden had with Wisniewski or where they thought he might be. But Wisniewski's friends say Jorden was her ex-boyfriend and she feared him.