A Maryland woman charged with pushing her 3-year-old son in a park swing until he died was found not criminally responsible by a judge on Monday, a prosecutor said.

Romechia Simms, 25, pleaded guilty to involuntary manslaughter in Charles County Circuit Court, said Tony Covington, the county prosecutor. She was then ruled not criminally responsible, Maryland’s equivalent to not guilty by reason of insanity.

Simms was ruled not to be a danger to herself or the community and was freed on a conditional release, Covington said.

Police found Simms pushing her dead son, Ji’Aire Lee, in a swing in a La Plata park last May. The child had been in the swing for some 40 hours and died of hypothermia and dehydration. La Plata is about 35 miles south of Washington.

Covington said the judge ruled after receiving mental evaluations that included one from the Maryland Office of Forensic Services. The Washington Post reported on Monday that the report said Simms suffered from schizophrenia.

Simms had been charged with first-degree child abuse, manslaughter and child neglect.