Born in Baltimore, Guirola received a Bachelor of Arts degree from William Carey College in 1973 and a Juris Doctor from the University of Mississippi Law School in 1979.

He was an Assistant United States Attorney of the Eastern District of Texas from 1990 to 1993.

On September 23, 2003, Guirola was nominated by President George W. Bush to a seat on the Southern District of Mississippi vacated by Judge Walter J. Gex III.

[1] On May 15, 2019, Chief Justice John Roberts appointed Guirola to the Foreign Intelligence Surveillance Court for a term beginning July 2, 2019.

[1] In 2021, he was appointed to a 5-year term on the United States Alien Terrorist Removal Court.