Hank Gerald, played by Raoul Bhaneja, was introduced in the Season 4 episode 'A New Life', where he marries Donna Sabine. As Ed walks her down the aisle at the outdoor ceremony, Donna reveals to him that she was the one to ask Hank to marry her.
Not much else is known about Hank's origins. 'A New Life' establishes that he works in the I.T. industry with his best friend/Best Man, Pete, and that he's a "techie". Hank and Pete "grew up in the same neighbourhood; went to the same school".
Hank seems to be very supportive of Donna's choice in career, in spite of the fact Donna admitted to Ed she was going to retire from the force following her honeymoon.
Near the conclusion of 'A New Life', Hank is shot twice in the back by Donna's ex-partner from her days with Vice, but he survives the attack.
Hank's final appearance is in the Season 4 finale, 'Slow Burn', where he appears briefly with Donna at an SRU picnic.
Though it is never addressed in the series, Hank is now a widower due to the events of "Keep the Peace, Pt. 1".