Days later, Mr Blancornelas was ambushed in his car by gunmen, Barron among them, who killed his bodyguard and badly wounded him.

ECONOMIST: Kidnapping and murder are the drug-dealers�� weapons

Mohammad Saaili Shibin was the chief negotiator for a group of pirates who took four Americans hostage aboard their yacht and later killed them.

NPR: FBI: Agents Fell To Deaths Training Off Va. Coast

In some cases, access codes were widely known because residents regularly gave them to guests and workers who cut lawns, killed pests, walked dogs, cleaned houses and delivered pizza.

WSJ: Should You Buy in a Gated Community?--WSJ House Talk

One difficult case was that of Ronald Bucca, a fire marshal with the New York City Fire Department who was among the first responders and one of hundreds of them killed.

NPR: Police Memorial Wall Comes With Some Tough Calls

"The people who are there will surround the families and take care of them, the ones who have had loved ones who were killed, " she said.

CNN: Fort Hood, a home for thousands

One episode was based in part on Susan Smith, the South Carolina mother who killed her two young sons by driving her car into a lake with them strapped inside.

CNN: Andrea Yates case: Witness at heart of appeal explains error

When paramedics who rushed to the home found the bodies of her other family members, Hendricks claimed Matthew had first killed them before turning the gun on himself.

NPR: APNewsBreak: Prayers Before SC Woman Killed Family