On the afternoon of November 5, a camera crew from the "To Catch a Predator" series, produced by investigative reporter Chris Hansen, accompanied a SWAT team to the house of a Texas prosecutor, Louis William Conradt Jr. Since 2004, the TV program has worked with local police departments and an online watchdog group called Perverted Justice that provides "decoys" -- adults who pose as teenage boys -- to lure suspected pedophiles to so-called sting houses.

Condradt, a five-term district attorney, had been an assistant prosecutor...