Broncos cornerback Perrish Cox has pleaded not guilty to sexual assault charges that carry a maximum punishment of life in prison. Attorney Harvey A. Steinberg entered Cox's plea Monday during a hearing in Castle Rock, in suburban Douglas County south of Denver. District Court Judge Paul King set a trial date of Oct. 18, six weeks into the NFL season if the labor dispute and lockout is resolved. Cox is charged with one count of sexual assault while the victim was physically helpless and one count of sexual assault while the victim was incapable of determining the nature of the conduct.