Irizarry was born on January 26, 1955, in San Sebastian, Puerto Rico,[1] and was raised in the Bronx in New York City.

Irizarry said she wanted to improve the quality of life in the neighborhoods in which she grew up, and specialized in drug and narcotics cases.

In 2002, Irizarry resigned from her judgeship to become the Republican nominee for Attorney General of New York, challenging Democratic incumbent Eliot Spitzer.

Although the American Bar Association determined her to be "not qualified,"[3] she was confirmed by the Senate on June 24, 2004, and received her commission on July 8, 2004, thereby becoming the first Hispanic judge in the Eastern District.

On December 15, 2010, Judge Irizarry sentenced Islamist militant and engineer Abdul Kadir, 58, of Guyana, to life in prison after the jury found him and co-defendant Russel Defreitas, a U.S. citizen born in Guyana, guilty of planning to blow up New York City's John F. Kennedy International Airport by exploding fuel tanks and pipelines underneath it.