Rachel and Grace are carjacked in E Malama due to Stan blackmailing a corrupt Housing Commissioner. This prompts Grace's father and Rachel's ex, Hawaii Five-0 Detective Danny Williams to get involved.
In Season Two, during Mai Ka Wa Kahiko, Danny's ex-partner, Rick Peterson forces Danny to kill Stan at gunpoint in exchange for Grace's life and Danny does it but it's later revealed that he actually shot Stan in the right shoulder, before shooting into the grass beside him to make Peterson think that he had killed Stan.
The family is visiting Stan's parents on the mainland in 2.21.
In the finale, Stan is planning to move the family to Las Vegas due to his work, forcing Danny to contact Rachel and tell her that he's planning on fighting her for custody of Grace.
Stan is currently living in Nevada while completing a real estate project. Rachel and the children are mentioned to have visited him during Christmas.