He attended St. Francis College and then received a Juris Doctor from the University of Buffalo School of Law.
Castorina gained citywide attention when he sued the City Department of Education after it proposed to take school buses away from middle schoolers in Staten Island.
[2] In 2015, Castorina was chosen by the Staten Island Republican Party to replace former Assemblymember Joseph Borelli, who had resigned after winning the vacated New York City Council seat of Vincent Ignizio.
[8][9][10][11] Along with Assemblymember Nicole Malliotakis, Castorina sued NYC Mayor Bill de Blasio concerning the use of the city's new ID cards by people without lawful residency status in the United States.
[13] In 2018, Castorina ran against Democratic Assemblyman Matthew Titone for Richmond County Surrogate Judge.