Susan Kuhnhausen, 51, ran to a neighbor's house after the confrontation Wednesday night. Police found the body of Edward Dalton Haffey, 59, a convicted felon with a long police record.
Officer Katherine Kent said homicide detectives have determined that Kuhnhausen killed Haffey in self-defense. She said a prosecutor is investigating but that the case is not expected to go to a grand jury.
Police said there was no obvious sign of forced entry at the house when Kuhnhausen, an emergency room nurse at Providence Portland Medical Center, got home from work shortly after 6 p.m.
Under Oregon law people can use reasonable deadly force when defending themselves against an intruder or burglar in their homes. Kuhnhausen was treated and released for minor injuries at Providence.
Haffey, about 5-foot-9 and 180 pounds, had convictions including conspiracy to commit aggravated murder, robbery, drug charges and possession of burglary tools. Neighbors said Kuhnhausen's size — 5-foot-7 and 260 pounds — may have given her an advantage.
"Everyone that I've talked to says 'Hurray for Susan,' said neighbor Annie Warnock, who called 911. "You didn't need to calm her. She's an emergency room nurse. She's used to dealing with crisis."