He told dispatchers he had last seen his daughter when he put her to bed at eight o'clock the night before - his sister checking on her two hours later.
It was in the morning that DiPietro returned to the room to find the crib empty.
DiPietro told dispatchers there was no way Ayla could have climbed out of the crib by herself.
Over the past two years pieces of evidence have been revealed - photos of blood in the apartment where Ayla was last seen.
Investigators say they have ruled out the possibility of an abduction, believing Ayla's disappearance is the result of foul play.
This is the largest missing person investigation in state history, a case that has drawn national attention.
No one has been charged in the case as investigators continue to search for Ayla.