Joe White

Joe White was a retired US Navy SEAL who held the rank of Lieutenant Commander and who is Lieutenant Commander Steve McGarrett's Commanding Officer as well as a father figure to Steve.

Biography
Joe made his debut appearance in the Season 2 premiere episode, Ha'i'ole where he was summoned to Hawaii by Detective Danny Williams who sought Joe's help in proving that Steve had not killed Governor Pat Jameson and Laura Hills.

During Ka Hakaka Maika'i, Joe summoned Special Agent Kensi Blye of NCIS: Los Angeles' Office of Special Projects to Hawaii to help lip-read a video file that had no audio which led Steve to discover that his father, Wo Fat and Governor Jameson were talking about someone or something named "Shelburne".

Joe also helped launch a rescue operation to save Steve during Kil'ilua when Steve, who had been lured to North Korea by Agent Jenna Kaye, was wounded and being captured by Wo Fat.

In the resulting process, Wo Fat killed Jenna before fleeing although the 5-0 team along with members of SEAL Team 9 were successful in saving Steve and bringing him back home to Hawaii.

In Pahele, Joe was brought before a board of inquiry for organizing an unauthorized military operation and retired from the Navy (with full benefits), much to Steve's distress.

It was eventually discovered that Joe had been to Japan, causing Steve to suspect that Joe was hiding something. Joe eventually revealed that he had helped Hiro Noshimuri fake his death by pretending to kidnap and hold him hostage in front of his son which was later revealed to be a plot to protect Adam from Hiro's criminal connections.

Joe later claimed to be "Shelburne" and he also told Steve that he was the one who had "murdered" Wo Fat's father before telling Steve that he hadn't told because he'd promised John McGarrett, Steve's father that he would protect Steve.

Joe eventually left Hawaii to protect Steve and his family. This later prompted Steve to leave the team albeit temporarily during Ha'alele and the H50/NCIS: Los Angeles crossover episodes, Pa Make Loa and Touch of Death as Steve sought to find Joe and discover what he was hiding, with the 5-0 team being left in Danny's care during Steve's absence. And meets his death in When the Light Goes Out, the House Is Dark and because of this. This makes Steve very mad at Agent Greer, the person who ordered him dead.

Season 2
In the Season 2 finale episode, Ua Hala, Joe returned and after the case was solved, took Steve to see the real Shelburne in Japan.

Before Steve went to knock on the door, Joe told Steve that he was sorry before abruptly disappearing. As soon as Joe was gone, Steve managed to get himself together and knock on the door, getting a shock when "Shelburne" turned out to be Doris McGarrett, Steve's supposedly dead mother.

Season 3
Joe later returned in the Season 3 episode, Olelo Ho'Opa'I Make where he, Steve and Catherine were present at the funeral of fallen Navy SEAL, Freddie Hart, Joe having served as Steve and Freddie's training officer and C.O., after a mission during which Steve and Catherine had gone to North Korea to get Freddie's remains back to the U.S.