Lex Luthor likely killed his father before ascending to take control of the family business in the lead-up to Batman v Superman: Dawn of Justice, according to the film's director.
Interacting with fans on the Vero social network, Zack Snyder agreed with one commenter's assessment that the film implies Luthor killed his dad.
"We feel the same way about Lex taking out his dad," Snyder wrote.
Since a lot of Snyder's take on the Superman mythology is inspired at least in part by the post-Crisis on Infinite Earths reinvention John Byrne spearheaded, it seems likely Snyder drew some inspiration from Luthor: The Unauthorized Biography, by writer James D. Hudnall and artist Eduardo Baretto.
Published in 1989, the one-shot, oversized comic detailed Lex Luthor's life and rise to power, framed against a story about his biographer being marked for death. In what has turned into an ironic touch, the cover was an homage to Donald Trump's autobiography The Art of the Deal.
The Unauthorized Biography depicted the unnamed Luthor patriarch as an abusive alcoholic, who died just days after a huge, mysterious insurance policy was taken out on him through the mail. Lex was named the beneficiary of the insurance and, shortly after his parents were killed in a car crash, the mechanic who found no evidence of tampering with the car quit his job to start a chain of auto parts stores that would make him wealthy.
No direct evidence ever proved that Luthor had been responsible for his parents' death, but it was strongly implied.
The car accident had been a reimagining of the family's death in the pre-Crisis era, but a later retcon -- Mark Waid and Leinil Yu's Superman: Birthright -- would bestow Luthor with the name Lionel (first used on Smallville). While the cause of death was changed (this time it was a heart attack, likely tied to a drug allergy), but the result was the same: heavily insured, he left Lex wealthy enough to pursue his dreams.
The fraught and sometimes abusive relationship between Lex Luthor and his father Lionel was a source of not-insignificant drama in the long-running CW superhero series Smallville, which tracked Clark Kent, Lex Luthor, and Lana Lang's teen years and eventually evolved into a kind of "Year Zero" origin story for the heroes of the DC Universe.
Batman v Superman: Dawn of Justice is currently available on Blu-ray, DVD, and streaming services. The DC Extended Universe continues with Aquaman on December 21st, Shazam on April 5, 2019, Wonder Woman 2 on November 1, 2019, Cyborg in 2020, and Green Lantern Corps in 2020.