PATERSON, N.J. (CBSNewYork/AP) – A northern New Jersey mom has been charged with aggravated manslaughter for the March 24 death of her four-month-old son.

According to prosecutors, Karen Stewart, 21, of Prospect Park allegedly beat the boy to death because he would not stop crying.

Stewart initially faced aggravated assault and child endangerment charges after the alleged beating occurred.

MORE: Passaic County Prosecutor’s Office Statement (pdf)

But Passaic County prosecutors recently added the aggravated manslaughter charge after reviewing the results of the boy’s autopsy, though they wouldn’t provide further details on what led them to file the new count.

Stewart faces up to 50 years in prison if convicted on all three counts. Her bail was raised from $200,000 to $550,000 when the aggravated manslaughter charge was filed.

It was not clear Tuesday if Stewart has retained a lawyer.

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