Morales says her son told her on Christmas Eve that he wanted to kill someone. She says she tried to calm him and get him to return to a Brooklyn halfway house.
Anthony Maldonado, of Palisades Park, N.J., was stabbed early Saturday while visiting a Harlem housing project.
Morales says her son was paroled from a prison near Buffalo in May after serving five years for assault.
In August, he was charged with punching a man in Manhattan.