The parents of a 1-year-old western Pennsylvania boy who authorities said died after he was intentionally “dosed with methadone” have pleaded guilty to third-degree murder.

Tracy Humphreys and Thomas Snelsire, both 47-year-old Baldwin residents, face standard-range prison terms of 16 to 20 years due to their criminal records when they are sentenced in Allegheny County court on Jan. 11, the Tribune-Review reported.

Assistant District Attorney Lisa Carey told a judge last week that Tommy Snelsire’s death wasn’t caused by accidental contact with the methadone, fentanyl and cocaine found in his system. Carey said investigators found a syringe used to administer medicine to children and a pill bottle used to mix liquid Tylenol and methadone together.

Thomas Snelsire had been under federal investigation at the time and was sentenced to 10 years after pleading guilty to drug trafficking in October. Defense attorney Patrick Thomassey asked the judge to run the murder sentence at the same time.

“It doesn’t matter what you do to Mr. Snelsire,” Thomassey said. “He’s going to be in jail for the rest of his life. He’s going to have to live with what he did to his toddler.”

Snelsire, who cried throughout the proceeding, said, “I’m so sorry. I’m just so sorry to everyone.”

Humphreys’ defense attorney, James Sheets, called the child’s short life “tortuous” and said he was “as appalled as everyone else in the room.” But he said his client was “accepting, to the extent she can, her role in the death of that little boy.”

Humphreys sobbed as she spoke directly to relatives, saying “I cannot ever give your grandson back. I’m so sorry.” She insisted, however that the defendants loved the child, even after a relative shouted back, “No, you didn’t.”

“We loved Tommy,” Humphreys continued. “I don’t know why God lets some people live and lets some people die. I’m alive, and I don’t know why I am and he’s not. I never meant for life to be this way.”