CAMDEN, N.J. — A woman who had admitted to drug use and recently regained custody of her toddler decapitated the boy, put his head in her freezer, and fatally stabbed herself as officers stood outside her home, officials said Wednesday.

Chevonne Thomas killed her 2-year-old son, Zahree, and called 911 just after midnight, then fatally stabbed herself while police officers were outside the house, police said.

In the 911 call, she said repeatedly ‘‘I did it, I did it,’’ said Jason Laughlin, spokesman for the Camden County prosecutor.

Results of toxicology tests will be needed to determine whether Thomas was high on drugs at the time.

Thomas, 33, had lost custody of Zahree in November 2010 after allegedly leaving the baby unattended in a car and admitting to police she had smoked marijuana laced with PCP and blacked out in a nearby park, authorities said.

She regained custody of the boy in April, Laughlin said.

Officers found Zahree’s body on the first floor, then located his head in the freezer.