Justin Pearson was born on August 20, 1975 and initially raised in Phoenix, Arizona by his parents. He was an only child and went by the nickname J.P. Pearson has stated he liked music and the aesthetics of rock music since he was little. Around ten his mother's cousin let him borrow a guitar, and he eventually moved onto bass. He also began skateboarding and listening to the "Thrasher" skate/rock compilation tapes with bands like Septic Death, the Sex Pistols, The Misfits, and Suicidal Tendencies. He has stated he was especially drawn towards the music that touched on social politics. Pearson also got into break dancing and early rap like Run DMC and the Beastie Boys, as well as developing an interest in metal. In Phoenix he lived a couple blocks away from some of the members of Slayer.