A sheriff’s deputy appeared emotional, and people sitting in the back row of the courthouse for unrelated cases gasped. In court, Simms, who has schizophrenia, wiped tears from her face as a prosecutor detailed the evidence against her, describing how the boy was taken to the medical examiner’s office still sitting in the swing because his body was too stiff to remove. Under a plea agreement accepted in Charles County Circuit Court on Monday, a judge found Simms not criminally responsible, Maryland’s version of an insanity defense. The 3-year-old died of hypothermia and dehydration. Simms, 25, was hearing voices as she pushed her son, Ji’Aire Lee, in a bucket swing for more than 40 hours, including in the rain, in May. Romechia Simms, the Maryland mother found pushing her dead child on a swing in La Plata last year, will remain free and continue receiving mental-health treatment instead of going to prison.