Perhaps the biggest enduring mystery of the Cleveland kidnapping case centers on the circumstances behind Amanda Berry's pregnancy and childbirth while in captivity. Well, today police sources said that the child was indeed born inside the house of Ariel Castro, with Berry giving birth in a small inflatable swimming pool. CBS News also reports that fellow kidnap victim Michele Knight was forced to assist in the delivery.

NewsChannel5 in Cleveland adds that their sources claim there were "multiple" pregnancies among the three women, but most ended in miscarriage. No exact figures were given, but previous reports had said that there were at least five pregnancies during the decade the women spent in captivity. It's not known if any other babies were born alive, or if were any other attempts to give birth. Police have said that a now-completed sweep of the house and property turned up no evidence of human remains.

Sources also told the Cleveland Plain Dealer that the women and child were occasionally taken from the home while in disguise, and that the owner Ariel Castro, would leave doors unlocked to "test" the women. It's not know if that's how Berry managed to get help and escape on Monday.

As more gruesome details about the Castro family emerged on Wednesday, Berry and her daughter returned home, but decided not to speak to the media as originally planned. (Another one of the women held at the home, Gina DeJesus, was expected to return home Wednesday afternoon.) Prosecutors plan to file formal charges against the three suspects on Wednesday, with an arraignment on Thursday morning. Police say they are focusing all their attention on Ariel Castro, suggesting that his brothers may not have been directly involved. (Although other charges could be filed against them.)