A 28-year-old Carbondale woman who police said smoked embalming fluid-laced marijuana the night her 2-month-old son died in her bed in July waived her right to a preliminary hearing Tuesday.

Earlier this month, police charged Thalia Matos with involuntary manslaughter and endangering the welfare of a child — her son, Royce Coxton.

Officers responded to 185 Fallbrook St., Apt. 303, on July 14 for a report of an unresponsive infant, and Coxton later died at Geisinger Community Medical Center in Scranton, police said.

During an interview with investigators, Matos admitted using marijuana and vaping inside her home.

Additionally, investigators found a marijuana cigarette — which appeared to be discolored — in the kitchen area inside Matos’ apartment. Detectives noted that adding formaldehyde to rolling papers of marijuana cigarettes will discolor them and that some people spray marijuana with embalming fluid as a way of furthering intoxication from the substance, according to the criminal complaint.

Ashley Matos said she and her sister, Thalia Matos, smoked a marijuana blunt and drank alcohol slushies, according to the criminal complaint. The results of a chemical test indicated Thalia Matos had THC — the main psychoactive compound in marijuana — and formic acid in her system.

Matos, who was previously released on bail, is next scheduled to appear in court on April 10 at 9 a.m. as her charges have been moved to the Court of Common Pleas, Lackawanna County Deputy District Attorney Bo Loughney said.

Matos’ conduct constituted a gross deviation from the standard of care required of a caregiver responsible for the safety and welfare of an infant, and this negligence directly contributed to the child’s death, investigators allege.

Photographs taken shortly after Royce was admitted to the hospital showed lividity — the pooling of blood following death — on the left side of the his face, and blanching — a mark indicative of pressure placed against a part of the body prior to death for an extended period of time — on his back near the shoulder blades, according to the criminal complaint.

Lackawanna County Coroner Tim Rowland listed the cause of Coxton’s death as “asphyxia due to mechanical compression due to co-sleeping” and ruled the manner of death as homicide.