Denver Broncos defensive end Antonio Smith is under investigation in Texas over a criminal allegation the local sheriff described Thursday as ''sexual in nature.'' Smith has not been arrested and no charges have been filed. Fort Bend County Sheriff Troy Nehls said a complaint was made against Smith in November and it was ''sexual in nature.'' After its investigation, the sheriff's office forwarded its findings to the county District Attorney's Office in February. When contacted by the Denver Post, District Attorney John Healey declined to discuss the nature of his office's investigation or confirm its target. More...