A pig farmer has been found guilty of murdering his wife with a rake.
Prosecutors said Todd M Mullis had plotted to kill Amy for years after discovering she had been unfaithful.
The 39-year-old was discovered by her 13-year-old son with a corn rake sticking out of her back on the couple's farm, around 40 miles west of Dubuque, Iowa, last November.
She had been impaled at least twice and possibly three times, according to the forensic pathologist who examined her body.
Jerry Fisher, a hog farm field manager, admitted to the jury he was having an affair with the 39-year-old at the time of her death.
He added that his lover was afraid of her husband.
“I knew she wasn’t happy,” he told the Dubuque County Courthouse. "She said she felt like a slave or a hostage around there."
He said Ms Mullis had wanted to leave her husband, adding: “One time, she said if he ever found out [about the affair] she would disappear.”
The court heard the murder weapon had four prongs but there were six puncture wounds in the victim’s body, leading medical examiners to conclude that she could not have fallen on the object.
Ms Mullis’ brother told the court his brother-in-law was a controlling husband.
Detectives also found that the 39-year-old told friends about difficulties in her marriage.
Mr Mullis guilty of first-degree murder, after the jury deliberated for more than seven hours over two days.
The conviction carries a mandatory sentence of life in prison, without the possibility of parole.
Additional reporting by agencies
