Police say Calista Springer died Feb. 27 in the Centreville fire.
McDonough's predecessor charged the couple with manslaughter and first-degree child abuse. They still face the child-abuse charge.
Attorneys for the two did not immediately return messages seeking comment Thursday.
Anthony Springer has said Calista had special needs and was restrained to protect her from unsafe behavior at night. Other relatives and friends have said the girl's parents abused her.