Castile was a regular marijuana user who died with high levels of THC, the drug’s chemical component, in his system. ... ...Castile was open about his marijuana use, and posted pictures of it on his Instagram account in 2012. It says he lied on his application for a firearm permit by denying he was “unlawful user of any controlled substance.” ...Yanez smelled marijuana in Castile’s car after pulling him over, and Castile appeared unable to focus or follow commands. Castile ignored the officer’s repeated demands not to reach for the .40 caliber semi-automatic handgun in his pocket.