The 33-year old mother called 911 to admit decapitating the boy just minutes before stabbing herself to death.
Authorities say the recorded conversation shows Chevonne Thomas initially blamed her boyfriend for killing Zahree.
But she quickly admitted she was the one responsible.
“You know what, I did it, I’m lying, I’m lying, I’m lying, I did it,” Thomas said in the call to emergency dispatch that was released Wednesday night.
The first officers on the scene found the toddler’s body on the first floor of the home.
He had been beheaded and stabbed several times.
Upstairs officers could hear Thomas still on the phone with 911.
The officers were unable to reach her before she stabbed herself in the throat.
During a search of the home, officers discovered the boy’s head in the freezer.
The coroner’s report shows the boy was alive when he was decapitated.
Court records show that in 2010, Zahree was taken away from Thomas because she left him alone in a car after she took drugs and passed out in a nearby park.
Thomas was ordered to undergo treatment for substance abuse and mental health disorders, according to the Department of Children and Families, but eventually regained custody of Zahree, the Associated Press reported.
Court records show Thomas faced dozens of judgments and liens filed in civil court in New Jersey dating back to 2002, according to The AP.
Neighbors say earlier in the day Thomas was outside blowing bubbles with her son.