Joann Cunningham faces up to 60 years in prison for the April murder of her son.
The officer unintentionally shot the shoplifting suspect's mother during a confrontation inside a home, authorities said.
The couple's friends purchased what they believed was a baby bouncer at the thrift store. Instead, the sealed box contained a rifle.
After previous denials. Martin Hyde has admitted to telling a group of tennis players from Puerto Rico to "speak English" and go "cut the grass."
A researcher calls the findings "meaningful but small."
