Johnny graduated from the University of California, San Diego in 1991 with a B.A. in Political Science; Graduated cum laude from Thomas Jefferson School of Law in 1996; began his career as a prosecutor with the Guam Attorney General’s Office in 1997; worked as an associate attorney with the law firm of Calvo & Clark (Guam); joined the Santa Clara County (SCC) D.A.’s Office in 1999. Johnny has also been involved for many years with the local bar associations and the SCC High School Mock Trial Competition.

Johnny has worked with local law enforcement to hold gun buyback events that have resulted in over 4,000 firearms being removed from SCC communities and has also worked with the California Department of Corrections and Rehabilitation in collecting over 1,500 cell phones to donate to local domestic violence shelters. Some of Johnny's favorite projects include the D.A.’s Law Related Education program which helps teach 5th graders about law and government and the Parent Project which helps parents with difficult adolescent youth. Johnny also currently serves as the President for the Northern California Chapter of the National Asian Pacific Islander Prosecutors Association (NAPIPA) and as well as Vice President of NCC-NPIEN.