The Santa Cruz County Sheriff's Office said Thornton's cause of death was "determined to be seawater drowning," and that it had been ruled an accident.
Across California, dozens of such studies are in limbo thanks to a little-known government panel that monitors research on federally restricted drugs and addiction treatment.
A Long Beach rocket and explosives hobbyist who crafted a homemade bomb that killed his ex-girlfriend, injured two other women and obliterated an Aliso Viejo day spa was ordered Friday to spend the rest of his life in federal prison.