Jason Duclair is a minor antagonist who is an arson expert. He first appears in the 16th episode of Season 5 of Hawaii Five-0, Nanahu after he killed a couple in their own home with a meticulous arson attack. The extent of his arson attacks are revealed with the help of an ATF agent who helps the Five-O team with their investigation.
He next appears in Season 6, episode 2: Lehu a Lehu where an admirer of Duclair (Andre Trout) helps him escape from prison by leveraging the Five-O team. The Five-O team try to save Duclair after it is revealed that Trout wants to kill Duclair instead of becoming his apprentice, but both Trout and Duclair escape the struggle. After a failed search, Duclair ends up turning himself back in and giving Trout's ashes to McGarrett, resulting in Duclair back in prison.
He appears again in Season 6 episode 21: Ka Pono Ku'oko'a, where a chemical spill leads to the escape of 6 prisoners, including Duclair and Adam Noshimuri who are initially shackled as a pair by the wrist. They eventually break the shackle and separate. Towards the end, Duclair returns to save Adam from the Yakuza. Duclair takes some heavy fire and ends up on the ground and looks to be dead, however Grover checks his pulse and calls for medical help, implying he is alive.
Duclair's final appearance is in Season 8 episode 1 where he again escapes from prison with the help of Aaron Wright , a computer hacker who hacks into the prison security system and allows Duclair to walk out. Duclair is initially employed by a drug trafficker to help find the culprit behind an amateur arson attack on one of his drug labs. Duclair turns on the trafficker and Aaron Wright, killing the trafficker and attempting to kill Aaron Wright until Five-O get there to stop him. Duclair escapes into the woods and lights bush fires for cover, it quickly turns into an out of control wildfire. Five-O find Duclair but with no way out of the fire they hold up in a cabin. Duclair manages to escape the cabin and runs out into the wildfire. Five-O eventually escape. The news report afterwards confirmed Duclair's death.