A Douglas County judge Wednesday sentenced a 29-year-old Littleton woman to 36 years in prison in the fentanyl overdose death of her 22-month old son in 2022.

Judge Ryan Stuart sentenced Hanna Gilmour, 29, on convictions of felony child abuse resulting in death and misdemeanor child abuse in the death of her late son, Layton Gilmour, according to a 23rd Judicial District Attorney’s Office news release.

In November 2022, the child’s father, Jacob Birkbeck, arrived at a Littleton apartment for a custody change. There, Birkbeck noted the child “didn’t look right.” Gilmour laughed in response and claimed the toddler was sleeping, according to judicial district officials.

Authorities said Birckbeck arrived at his mother’s home to find his son not breathing. Birckbeck called 911, before the child was pronounced dead later.

Investigators searched Gilmour’s apartment, who she shared with her boyfriend. Authorities found the apartment littered with cocaine, illegal mushrooms, marijuana and fentanyl, according to the judicial district.

Prosecutors believe the child died due to fentanyl exposure while crawling on the ground.

“This was a senseless and preventable tragedy,” Chief Deputy District Attorney Jake Adkins who prosecuted the case, said in the release. “Every parent has a responsibility to protect their child. Instead, their mother created an environment so dangerous that it cost her son his life.”