A five-year-old kindergarten boy in New Jersey brought 30 packets of heroin to school on Monday, police say.

A teacher at the International Academy of Trenton caught the child playing with what she thought was a candy wrapper, when she found 29 other white packets in his lunchbox that turned out to be heroin, The Trentonian reported.

The student was taken to a local hospital, where he tested negative for opiates, police said.

Detectives are trying to determine where the boy got the drugs and have not charged anyone yet, according to The Trentonian.

Police officials declined to tell the outlet whether the boy is back in his parents’ custody or whether he is in the custody of Child Protective Services.

A string of drug overdose stories where young children have been endangered have been in the news.

Just last week in Ohio, a four-year-old child was left in the backseat of a car while two adults lay passed out in the driver’s seat and the front passenger seat due to a heroin overdose. The child is now in the custody of his great-aunt and great-uncle, the Associated Press reports.

Earlier this month, police officers in Alabama found a one-month-old child and three other children left alone because both parents were unresponsive due to drug overdoses. The police department that found the baby faced backlash when the baby’s aunt claimed her niece was being exploited because of a photo of the baby being comforted by an officer that went viral.