A 14-year-old girl ran away from her mother's home and disappeared without a trace. A farmer later discovered the young girl's remains in an Illinois barn.

A woman vanishes, and police suspect that her powerful ex-lover, a married man, was responsible. When investigators can't find the woman's body or the murder weapon, the FBI's only hope was to go undercover and turn brother against brother.

Street gangs in Washington D.C. enforced their territories with lethal violence. Authorities vowed to bring the entire gang to justice while the gang leader had fled to Africa.

Masked bandits pulled off a daring mid-day bank robbery. With no evidence leaving behind, the FBI forced their own luck.

A serial killer dupes FBI agents while eluding a nationwide manhunt.

A stranger snatched an eight-year-old girl as she played in her Tucson, Arizona neighborhood. Within hours, a drifter who was out on parole for abducting and molesting children, but he was nowhere to be found and time had run out.

Marine Captain Shirley Russell disappeared. FBI agents found her husband, himself a former Marine, was acting strangely. The FBI's intense investigation revealed a violent past.

New Jersey millionaire Frank Black flew to Florida to close a major business deal and never came home. FBI Agents learned of a mystery woman in Florida who was meet Black. Eventually they untangled a web of deceit that led to a vengeance killing.

FBI agents began investigating New York gas station mogul Gurmeet Dhinsa for gas pump rigging. They learned that he enforced his mob-like operation with brutal violence.

The decapitation of a young African-American male led the Miami-Dade PD and the FBI along a trail of murder. Investigators quickly discovered that the victim was a dissident member of a religious sect headed by a man calling himself Yahweh ben Yahweh, or God, Son of God.

Glendale, Arizona mall, local authorities and the FBI scrambled to recover its cargo of nearly a million dollars.

Police and FBI agents track a serial killer in a cross-country manhunt.

A television producer was gunned down in his New York office. Four years later and a continent away, a man told Los Angeles police he had been hired to murder two exotic dancers. Investigators linked the two crimes and uncovered a businessman willing to kill to protect his interests.

A armored car robbery near New York City left one guard dead and another critically wounded. The FBI suspected a large group of domestic terrorists with a history of violent crime.

A California man was found dismembered. The murder suspect was found six months later when he was caught robbing an Arizona bank and sentenced to life. When he escaped from prison, the FBI led a manhunt for the killer.

David Wilkey was shot to death on a hunting ground in rural Virginia. When this seemed to be an accident, investigators suspected foul play. Two years later, a man contacted North Carolina FBI agents with a complex story of conspiracy and murder-for-hire.

On a summer night in 1990, the body of a suspected drug courier was discovered burning in a Minnesota alley. The FBI worked with local police to uncover a crime ring run by a drug lord who used violence and intimidation to keep those around him silent.

In the season 3 finale, Drug gangs terrorized Harlem, New York neighborhoods. After a 10-year-old boy became a victim, the FBI formed a task force called C-11, designed to dismantle the gangs.