The law increases the sentences for an adult convicted of torturing a child, changing the maximum sentence to life in prison.
Nixzmary died in 2006. Her mother is serving a sentence of up to 43 years in prison for doing nothing as the battered and malnourished child lay dying in their home. The girl's stepfather is serving 29 years on a manslaughter conviction for delivering the fatal blow.
"Signing Nixzmary's Law cannot bring back the life of a young girl, but it does send a message that such abuse of children will not go unpunished,'' Paterson said. "It is my sincere hope that a law such as this and continued vigilance by our law enforcement officials will help prevent tragedies like this from happening again.''
The law amends the murder statute to add a section for the murder of a child less than 14 in an "especially cruel and wanton manner,'' eliminating the chance of parole.
The previous maximum for the crime, a charge of first-degree manslaughter, was 25 years, with the chance of parole.
Nixzmary's Law was overwhelmingly supported in the Assembly and Senate earlier this year.
Paterson signed several other bills and vetoed two that he said would have cost New York $1 million, at a time he and the Legislature need to close a $3 billion deficit. They include vetoing a bill that would have provided an additional opportunity for public input when the state seeks to close a hospital, as it did under an extensive program to reduce health care costs and move more care to less expensive outpatient and clinic care.
Paterson also vetoed a bill that would have printed and distributed regional farm guides to farmers and tourism offices.