<Li> Kekoa Kekumano as Nahele Huikala (season 5--present), a homeless teen who steals McGarrett's car (in the episode Poina ʻOle), had the car stripped and sold the parts . It is later learned that his father committed a murder revealed in the season six episode "Hana Keaka" where he was the sole eyewitness moments after his father regained full parental custody after being released from Halawa Correctional Facility . </Li> <Li> Christopher Sean as Gabriel Waincroft (seasons 4--6), a powerful fugitive crime figure who is the brother of Dr. Malia Waincroft and the brother - in - law of Chin Ho Kelly, whose father Gabriel is revealed to have killed as part of a gang initiation 15 years ago . In Pa'a Ka' ipuka I Ka' Upena Nananana, he was badly wounded & died in surgery from cardiac arrest . </Li> <Li> Carol Burnett as Aunt Deb (seasons 4--6), McGarrett's aunt from 2013 until her death from cancer in the January 15, 2016 episode . </Li> <Li> Julie Benz as Abby Dunn (seasons 6--7), an Internal Affairs agent who is investigating Five - 0 undercover as an SFPD detective . </Li>

Who were the original cast members of hawaii five o