Angel Guerrero was taken by mistake when the woman arrived at his elementary school and took him without knowing what the child she was to care for looked like, said Sgt. David Cannan.
The mix-up caused alarm when Angel's grandmother came to the school and was told someone had already picked him up. Police issued a missing child alert, and his name and picture were broadcast live on several TV stations.
Meanwhile, the babysitter had no idea she picked up the wrong child until her employers returned home and did not recognize Angel.
"The babysitter said 'This is your son,' and the parents said, 'No, this is not our son,"' Cannan said. When the parents saw Angel's picture plastered on their TV screen, they immediately called police.
School officials didn't notice the mix-up, Cannan said, because Angel willingly left with the woman.
Meanwhile, the boy she was supposed to pick up waited for several hours until school staffers called an uncle to pick him up.
"There's a lesson here," Cannan said. "What an opportunity to tell parents to talk to their kids, and communicate with their caregivers. This young child was full of trust, and he sees an older, caring adult and just walked off with that person."