The staff
An aristocracy of great martial artists, not a monarchy. Every class here, kids to competition, is taught by the people below, under one collective standard.
Jay ShellhammerBlack Belt · Co‑Owner
Karla ShellhammerBlack Belt · World Champion
Josh HalsteadBlack Belt · Muay Thai
Makilla JonesBlack Belt · World Champion
Roberto VargasWrestling · NCAA Division I
Brendon TierneyBlack Belt · Gi & No‑Gi
Frank RamseyBlack Belt · MMA 17-3
Italo Lima CostaCoach · Profile coming
Osvaldo “Queixinho” MoizinhoCoach · Profile coming
Black Belt · Co‑Owner
Jay is a Brazilian Jiu‑Jitsu black belt with over 20 years on the mats and a co‑owner of High Street Jiu Jitsu. A U.S. military veteran, he has tested himself in more than 150 matches, winning several Fight To Win events and multiple IBJJF titles, including black‑belt gold at the IBJJF American Nationals. He has competed all over the country, often alongside his wife and fellow black belt, Karla.
Black Belt · World Champion
Karla is a Brazilian Jiu‑Jitsu black belt and a multi‑time Master World and National Champion in both Gi and No‑Gi, with over a decade of experience and more than 230 matches competed. A co‑owner of High Street, she leads both the adult and youth programs. Her classes are dynamic and detail‑driven, built on connection, creativity and discipline.
Black Belt · Muay Thai
Josh brings more than 25 years across Muay Thai, Brazilian Jiu‑Jitsu, boxing and judo, and earned his Checkmat black belt in 2023. He competed professionally in IKFB Muay Thai and MMA, and over 15 years of coaching he has cornered fighters from organizations including WEC, PRIDE, K‑1, Bellator and the UFC. He spent most of a 20‑year career as a self‑defense instructor in law enforcement.
Black Belt · World Champion
Makilla worked from white to black belt in eight years and emphasizes using an opponent's reaction to apply the fundamentals. She is the IBJJF purple‑belt adult gi world champion (2022), an ADCC Phoenix Open champion, and a brown‑belt no‑gi Pan silver medalist, with a four‑year high school wrestling background. Most recently she added wins at Submission Battleground and Arte Suave.
Wrestling · NCAA Division I
Roberto was born and raised in Southern California and started wrestling at age seven. He wrestled at Cal State Bakersfield under head coach TJ Kerr, where he won in the Pac‑10 and qualified for NCAA Division I. In 2008 he began a professional MMA career out of Millennia MMA, competing in organizations including ShoXC and King of the Cage. He leads the wrestling room.
Black Belt · Gi & No‑Gi
Brendon began training in San Diego in 2000 and went on to compete professionally for a decade across the U.S. and Canada. After rediscovering the art at Ares Arizona, he earned his black belt under Professor Paul Nava in 2023. He teaches Gi and No‑Gi for both kids and adults with an energetic, technical and welcoming approach, and brings a striking system designed for grapplers.
Black Belt · MMA 17-3
Frank grew up wrestling in Montana, where he became an All‑State finalist, before going undefeated across boxing and kickboxing and launching an MMA career. Across 20 amateur and professional bouts he holds a 17 and 3 record, and he earned his Brazilian Jiu‑Jitsu black belt along the way. He loves coaching and helping athletes reach their goals.
Coach · Profile coming
Italo Lima Costa coaches at High Street, and his full profile is being written now. Want to meet the coaches before it lands? Call (805) 895‑4454, email info@highstreetjiujitsu.com, or start your free trial and step onto the mats.
Coach · Profile coming
Osvaldo “Queixinho” Moizinho coaches at High Street, and his full profile is being written now. Want to meet the coaches before it lands? Call (805) 895‑4454, email info@highstreetjiujitsu.com, or start your free trial and step onto the mats.