A spotlight on true-crime stories of love affairs gone wrong, spouses driven to kill and other crimes of passion.

An adulterous husband trains his lover in the art of killing in Daytona Beach, Fla.; a woman falls in and out of love in Sydney, Australia.

A gigolo sets a trap using his attractive girlfriend as bait in Sarasota, Florida; a South African doctor uses his medical knowledge to kill.

A cheating wife asks her lover for a deadly favor in Centre Hall, Pennsylvania; a murder is planned for a Christmas party in Lincolnshire, England.

In Oregon, a karate instructor's affair leads to some killer blows; a millionaire hides a secret in England.