Police have arrested a 23-year-old woman they say killed her newborn baby before throwing him in the trash.

The baby boy was found last month at a recycling plant in Westchester County. 

He had been dubbed "Baby Angel" as authorities searched for his killer and clues to his identity.

The child was found in a plastic bag mixed among cardboard at the Brookfield Recycling Plant in Elmsford.

Police said Wednesday that the woman, who has a 2-year-old daughter, hid the pregnancy. The girl is now in the custody of child services.