A Maryland mother has confessed to giving her 5-year-old son a lethal overdose of antihistamine last year before setting her car on fire with him inside of it.

35-year-old Narges Shafeirad pleaded guilty Thursday to first-degree murder in the death of little Daniel Dana.

An autopsy has revealed that he died of a Diphenhydramine overdose in June of 2015 after she forced him to swallow medication containing the drug.

She then tried to make it look like a wreck and put her son’s body inside the car, before dousing it with gasoline and setting it alight beside a Montgomery County highway. Responding officers and firefighters found her lying outside the car.

At the time, she’d been going through a divorce and a custody battle with her husband.