Dekalb Police spokesman Officer Jason Gagnon said police searched the area of the station and found nothing.
Police located the woman's boyfriend who eventually led police to a storm drain where the baby was recovered.
The baby was rushed to Children's Hospital where it is in serious but stable condition.
Police said the baby had probably been in the drain two hours.
Police charged the boyfriend, 19-year-old Landis Stewart-Moore with cruelty to children.
The mother who has not been identified, will also be charged, according to police.