A Vermont-based mother and her boyfriend were arrested Tuesday for filling their 13-year-old disabled son's IV bag with alcohol, killing him. Reuters/Michael Dalder

A Vermont-based woman and her boyfriend were arrested and charged with second-degree murder on Tuesday for adding alcohol to the IV bag of the woman’s disabled son, leading to his death. Isaac Robitille, 13, was discovered dead in August and the police arrested the mother, counting her responsible for his death, after a two-month long investigation.

Melissa Robitille and her boyfriend, Walter Richter III, both 38, were arrested after the death of Isaac, who was born with several physical handicaps and a brain abnormality. The 13-year-old teenager, who was fed with tubes and needed IVs to keep him alive, was in constant need of caretakers, local police said, according to the Burlington Free Press. The autopsy reports showed that the teenager's blood contained 0.146 percent alcohol.

Police who were called to the spot by the mother early morning on Aug. 22 after finding her son dead said that the couple had administered the alcohol to him by filling his IV bag with it. The toxicology report said that the cause of death was alcohol while it stated the manner of death to be a homicide.

While local reports did not clarify whether the couple had a lawyer yet, police reportedly told the Burlington Free Press that there was no information yet on the bail being arranged or its conditions.