This report aired Dateline Friday, Feb. 3, 9 p.m. We want to warn you some of what you'll see is explicit. But parents need to know what their kids can confront when they sit down at the computer.

Predators scouring the Internet, targeting children for sex: It's a national problem that Dateline has helped uncover. We got such an overwhelming response from our last investigation— some 15,000 emails from parents, grandparents, teachers and law enforcement— telling us to "keep up the good work," and "keep the issue alive." On Wednesday night, April 26, Dateline is back with the fourth undercover investigation. This time, we traveled to small town America. Even far from the big cities and suburbs, vulnerable young teens are not far from danger. A warning: some of what you're about to see is explicit.

The Cordes couple seemed solid on the outside, but with a deep crack running beneath the surface. They bought a house on an island in the sun and seemed to be in paradise... until the night the wife disappeared. Dennis Murphy's reports.

This report airs May 3, Wednesday, 9 p.m.. It's the latest in Dateline's month-long series of undercover investigations: children at risk from grown men online. We're back in small town America, where the investigation leads us to one of the most disturbing cases we've ever found. A warning: some of what you're about to see is explicit.

This report aired May 10, Wednesday, 9 p.m. An encore presentation airs May 31, 9 p.m.: It's the latest in Dateline's month-long series of undercover investigations— children at risk from grown men online. This time, we take our hidden cameras to Florida. We thought we'd seen and heard just about everything, but what we found there surprised even our own Chris Hansen. A warning: some of what you're about to see is explicit.

This report airs May 17, Wednesday, 9 p.m.: This month, millions of people have been watching our investigations into computer sex predators — among them, some of the suspected predators themselves. And what's most surprising is that even knowing that they may be walking into a sting is not enough to keep some of them away. Tonight, we're back in Florida, where we started our investigation last week. We want to remind you that some of what you'll see and read is explicit.

A man is accused of killing his beautiful wife on a moonlit beach walk and then shooting himself to cover up the crime, Dennis Murphy reports.

Did a distinguished doctor kill his wife of 31 years at a Wellesley pond?