An officer with the New York City Transit Police and his fiancée have been arrested and charged with second-degree murder in the death of the officer's 8-year-old son over the weekend.

According to CNN, the couple—identified as 40-year-old Michael Valva and 42-year-old Angela Pollina—reportedly left the boy in an unfinished and unheated garage overnight as outside air temperatures reached a low of 19 degrees Fahrenheit.

When the couple discovered the boy unresponsive in the morning, they attempted to perform CPR before calling 911. The boy was then transported to a nearby hospital where he was pronounced dead.

Suffolk County Police Commissioner Geraldine Hart said that the boy had suffered head and facial injuries that were not consistent with his father's account.

Both Valva and Pollina have pled not guilty.