After almost 20 seasons, Leroy Jethro Gibbs left NCIS. Mark Harmon may have left the show, but this isn't the end for Gibbs.

Viewers are curious to know who killed Leroy Jethro Gibbs’ family members in the CBS series, NCIS: Origins. The NCIS spin-off chronicles the early years of young Gibbs in the 1990s when he joined as a special agent at NCIS Camp Pendleton office.

NCIS: Origins tackled the character Leroy Jethro Gibbs’ (Austin Stowell) act of revenge on the cartel leader who murdered his wife and child. In the show’s ninth episode, named Vivo o Muerto, Leroy’s haunting heartache was exposed as he’s been dealing with the pain of his family’s murder from the beginning of the series.