According to police, the suspect is 23-year old Maria Oliva Guaman-Guaman, an Ecuadorian national who they say was living in the country illegally.
Spring Valley police Chief Paul Modica said Guaman-Guaman confessed to the crime.
"There were tears, but I can't really say she was remorseful," the chief said. "She told the investigator she didn't want the child, and later on she said, 'I can't afford another child.'"
The baby's body was found in a plastic bag at Brookfield Recycling in Elmsford, Westchester County on November 13 in what investigators have called a brutal homicide of a full-term newborn.
Investigators say DNA evidence positively linked the child to Guaman-Guaman. She was arraigned Tuesday night and ordered held without bail. A not-guilty plea was entered at the arraignment, a court clerk said.
A 2-year old was removed from her care and placed in child protective custody.
The police chief said the murder charge specifies death by strangulation, but he would not say how the baby was strangled. After the killing, he said, the mother left the baby's body in a recycling bin near her Spring Valley home, which was then taken to the center in Elmsford.
Modica said DNA and "50 to 60" tips helped them focus on Guaman-Guaman. A reward of $5,000 had been offered in hopes of identifying the child and the parents.
Investigators suspected early on that the baby boy may have been Hispanic.
Two items were found with the baby - a black skirt and a towel with a floral design. Although the clothes found with the baby are typically are sold and worn in the Hasidic community, investigators say sometimes the clothes end up in secondhand stores where they are bought by people in the Hispanic community.
They had said that sometimes women working for someone in Hasidic community are made to wear that type of clothing.
The chief said on Wednesday that the mother had not named the baby.
Modica said Guaman-Guaman is from Ecuador and was deported from the United States in either 2008 or 2009. He was not certain of her current immigration status. She was living with relatives, but not the father of the child.