The Grays Harbor County Prosecuting Attorney has declined to file charges against a Cosmopolis woman who shot and killed her son last summer.

Joann Rosalie Day shot and killed her son Jerry “Adam” Day on June 25, 2021, after mistaking him for an unknown intruder intent on doing her and her son harm. Day shot her son four times before recognizing him and calling the authorities. He was pronounced dead at the scene.

“After review of all of the facts, and after consultation with your agency, as well as several attorneys in my office, we do not believe we can prove criminal homicide,” said Chief Criminal Deputy Jason F. Walker last week in a letter to the Cosmopolis Police Department.

The letter states that multiple charges, including murder and manslaughter, were considered but that, “the victim’s claim of defense cannot be disproven.”

According to police reports of the incident, Day was awakened by what she thought were sounds of a “scuffle” from her son’s room. She believed that “her son was fighting with someone,” and retrieved her weapon that she had stored under her pillow before investigating the noise. Upon exiting her room, she was forced to duck to the side while someone threw something at her, after which she noticed a man standing at the top of the stairs.

“The yelling and screaming combined with this man throwing things at her lead her to believe that someone was hurting her and her son and that she needed to ‘save him,’” says the police report.

According to Joann, Adam had been acting increasingly irrationally and violently in the weeks leading up to the shooting. He had a long history of mental illness and substance abuse that may have led to delusions and outbursts.

“There were times in her life where acts of violence and violent behavior occurred that made her fear for her safety,” said Cosmopolis Police Chief Casey Stratton.

Washington’s strong self-defense laws place the burden on the state to disprove self-defense beyond a reasonable doubt. According to Walker, he and Senior Deputy Prosecutor Tilloston declined to press charges after coming to the realization that they could not overcome this burden.

“Ms. Day was in her own home when she used her firearm. Afterwards, she was cooperative with the police and gave a statement after being advised of her rights,” said Walker. “To successfully prosecute a criminal charge, we would have to prove that she lied to the police, and that she knew she was shooting her own son.”

The Cosmopolis Police Department will retain the file on the incident indefinitely, and it will also be archieved with the state.