Where is Michelle Knight's son today? It's a question many have asked, but one with a confidential answer.

Each year in Cuyahoga County, there are more than 600 children taken from their homes, put into foster care and awaiting adoption.

Could Michelle's son have already gone through that process? He was likely 2 years old when Michelle disappeared, which could make him 13 today. Where is he now? Could Michelle be reunited with him?

Michelle Knight remembers the day her role as a mother possibly took an irreversible turn.

"My mother's boyfriend came home one day high and drunk and just decided to take out his frustrations on my son. How did he do it?

"He twisted my son's leg, and I heard it crack," said Knight.

Michelle's son entered into foster care.

"And then they tried to say I didn't protect him, but I did. I did all I could do," recalls Knight.

Betsie Norris from Adoption Network Cleveland says by law the county is required to come up with a plan to reunite a mother and child, which takes about a year.

"They'll work a reunification plan with the birth family hoping they can rectify whatever the circumstances were that brought the child into care, so that the child can go safely home," said Norris.

Michelle was likely going through that phase when Ariel Castro abducted her from a Family Dollar in Cleveland.

At that time, no one knew why Michelle disappeared. It could have looked like she abandoned her son. In cases when the mother isn't reachable for long periods of time, the county moves for permanent custody.

"The court weighs all the different factors, evidence, and, if they feel it's warranted, then they move forward to terminate parental rights, which then means the child is available for adoption," said Norris.

Is that what happened to Michelle's son? Could another family have adopted him while Michelle was held captive? It's an answer only Michelle knows.

"I loved my son with all my heart," said Knight.

By law, Michelle can be told whether her son is still in foster care or has been adopted. If he's been adopted, all that information is sealed and after a year, a probate judge says it is extremely difficult to reverse.