CAMDEN - The Department of Children and Families says the woman accused of decapitating her 2-year-old son before stabbing herself to death had passed drug tests as recently as June 29th.

Officials from DYFS claim a social worker last visited her home on July 3, and allegedly had no red flags to report.

Thomas lost custody of her son Zahree Thomas after being charged in 2010 with child endangerment. DYFS says it had been working with members of Chevonne Thomas' family to support the woman and her son, who were reunited under a court order in April.

They agency now says it will review its role in the case.

Police say they found the body of young Zahree Thomas early Wednesday morning on the first floor of his mother's Camden home. They found his head in the freezer.

Authorities say the 33-year-old mother fatally stabbed herself after calling 911 to report her son's death.

The 911 call from Chevonne Thomas was rambling and incoherent, but authorities say she made one thing clear: Her 2-year-old son had been stabbed, and she did it.

During the call, she first accused her boyfriend of stabbing Zahree, but then quickly recanted.

According to a recording of the call released Wednesday night she says, "You know what, I did it, I'm lying, I'm lying, I'm lying, I did it."

When asked if she takes medicine, Thomas said she used to take the antidepressant Prozac.

AUDIO: Camden mom called 911 before decapitating toddler, killing self