When Susan Kuhnhausen returned home from work one day earlier this month, she encountered an intruder wielding a claw hammer. After a struggle, the 51-year-old nurse fended off her attacker by strangling him with her bare hands.

Neighbors praised the woman for her bravery, and investigators said they believed the dead man — Edward Dalton Haffey — was burglarizing Kuhnhausen’s home.

But after an investigation, police now say the intruder Kuhnhausen strangled was apparently a hit man hired by her estranged husband — Michael James Kuhnhausen Sr. — to kill her.

The 58-year-old husband was taken into custody Thursday and charged with conspiracy to commit murder and attempted murder. He was ordered held on $500,000 bail.

Haffey had worked as a custodian under Kuhnhausen at an adult video store, according an affidavit filed by the Multnomah County District Attorney’s office.

Kuhnhausen and his wife were in the process of getting a divorce, and she told officers “her husband was distraught about the divorce and wanting to reconcile but that she was insisting on the divorce,” the affidavit states.

A background check showed Haffey had served lengthy prison terms for conspiracy to commit aggravated murder and convictions for robbery and burglary.

Inside a backpack Haffey left at the scene was a day planner with “Call Mike, Get letter,” scribbled on the week of Sept. 4, the affidavit said. Michael Kuhnhausen’s cell phone number was jotted on the inside of a folder, it said.

An emergency room nurse who lives in a southeast Portland neighborhood, Susan Kuhnhausen arrived home on the evening of Sept. 6 to find Haffey coming at her with a claw hammer.

She was struck in the head and wrested the weapon away, but the struggle continued and Haffey bit the nurse, according to police. A large woman, she was eventually able to get the slight Haffey into a chokehold and police later found him dead in a hallway. An autopsy revealed the cause of death as strangulation.

Police say she acted in self-defense.

There was no sign of forced entry into the home, but according to the affidavit, Susan Kuhnhausen offered an explanation for the lack of evidence of a break-in: Her estranged husband had the security codes for the home’s alarm system, and would have been able to disarm it.

Michael Kuhnhausen denies any involvement, the affidavit states.

Susan Kuhnhausen was out of town attending a nursing conference and did not immediately return a phone call seeking comment.

She left this message on her voicemail: “I’m not able to answer all the calls that I’ve received in the past few days. I’m being comforted by your concern and your support. I want you to know that our lives are all at risk for random acts, but more likely random acts of love will come your way than random acts of violence.”