[1] Seth Gecko was originally in prison prior to the events of From Dusk till Dawn but was broken out by his mentally ill younger brother (and partner in crime), Richie.

Despite being a hardened criminal, who robs and kidnaps without compunction, he is shown to have an apparent code of honor, only killing when he feels necessary and promising to eventually release a woman he and Richie had taken hostage.

In the original film, Seth and his unhinged younger brother Richie have just robbed a bank, and taken one of its female employees as a hostage.

After crossing the border into Mexico, they go to a bar called Titty Twister, where Seth is supposed to meet Carlos, his contact.

Sheriff Otis Lawson references Edgar McGraw's cold demeanor and distracted nature, including the murder of his father Earl.

In the From Dusk till Dawn video game it is revealed that sometime after the events of the film, Seth is arrested and condemned to life in prison for the murders Richie committed.