CAMDEN — A woman who decapitated her 2-year-old son and then fatally stabbed herself this week appeared to have overcome her drug problems in the months leading up to their deaths, state child services officials said Friday.

New Jersey's Department of Children and Families released more details Friday about the agency's involvement with Chevonne Thomas and her son, Zahree.

Police found the 2-year-old's body in the family's Camden row house early Wednesday. His head was in the freezer. Chevonne Thomas fatally stabbed herself in the neck minutes after placing a rambling 911 call in which she said she had stabbed her son.

The child services agency provided the following timeline of Zahree's brief life:

From late November 2010 to July 2011, the boy was placed with a relative after his mother left him unattended in a parked vehicle and later admitted using marijuana and the hallucinogenic drug PCP.

After Chevonne Thomas successfully completed substance abuse and mental health counseling, Zahree was returned to her in mid-July 2011. But he was removed from the home again in early August 2011 after his mother tested positive for PCP in a random drug test.

Over the next eight months, Chevonne Thomas completed a series of evaluations and therapy — and tested drug-free — and was given custody of Zahree in April 2012 with in-home support services. Her most recent negative drug tests came back at the end of June.

A caseworker last visited the home on July 3, and after continued positive reports, officials reviewed the case three weeks later preparing to close it.

"Our ongoing review does not reveal that any support systems involved with Ms. Thomas had any indications of relapse or noted any behaviors that could foreshadow harm to Zahree," DCF spokeswoman Kristine Brown said in an e-mail Friday.

Thomas told 911 dispatchers just before she stabbed herself that she was on the antidepressant Prozac but didn't take it that day.

"I didn't take it today, but I should have. I should have," she said.

Related coverage:

• Autopsy: Decapitation ruled cause of Camden toddler's death

• Frantic 911 call from Camden woman who allegedly decapitated her son: 'I did it, I did it' -- Audio

