Episode: 4x01 | Airdate: Mar 18, 2013
The FBI races to save 11 year old Leah Henry from a sexual sadist who kidnaps & tortures young girls on Interstate 10. The sadist's level of violence increases with each victim. The FBI knows there's not a moment to waste if they hope to find Leah alive.
Episode: 4x02 | Airdate: Mar 25, 2013
When a dozen young women turn up dead across St. Louis, police & the FBI work to piece together the identity of a sadistic serial killer. He plays a ruthless game of cat and mouse, taunting investigators, until his final kill which haunt many to this day.
Episode: 4x03 | Airdate: Apr 1, 2013
The FBI and Citrus County Sheriff's detectives search for missing 9 year-old Jessica Lunsford who disappeared from her bed in the middle of the night. Everyone's a suspect until investigators unearth a terrible secret that lies close to home.
Episode: 4x04 | Airdate: Apr 8, 2013
When Robert O'Dubaine is found shot to death, this apparent gangland hit unravels into a tragic case of betrayal and sends the FBI and Chicago police on the hunt for a lethal temptress who's hoping to elude authorities in the heart of paradise.
Episode: 4x05 | Airdate: Apr 15, 2013
When two young girls go missing from a small California town, the FBI and local police go on high alert searching out a serial predator before he strikes again. It will take the courage of one tiny hero to put an end to an evil killer who knows no limits.
Episode: 4x06 | Airdate: Apr 22, 2013
After 3 people are murdered in Jacksonville, the FBI and police track a man who dares to raft across the Rio Grande to seek refuge in a Mexican prison. His release sparks a worldwide manhunt for a murderer with the looks and charm to blend in anywhere.
Episode: 4x07 | Airdate: Apr 29, 2013
When FBI Special Agent Mike Clarke begins an Albanian serial murder investigation, his efforts leads to The Bronx, NY and the unsolved murder of Mary Beal. The NYPD and the FBI find themselves on the hunt for a possible intercontinental killer.
Episode: 4x08 | Airdate: May 13, 2013
When a 16-year-old girl is kidnapped at gunpoint by a vicious drug gang, Texas Police and the FBI launch an intense search. Weeks go by before a twist of fate leads investigators to her captors. Will they find young Lisa Rene before it's too late?
Episode: 4x09 | Airdate: May 20, 2013
When a police dispatcher mysteriously disappears from her Georgia home the FBI and local police launch a desperate search to find her. Inconsistent theories of her whereabouts make agents suspect that someone close to the investigation is misleading them.
Episode: 4x10 | Airdate: May 27, 2013
When several women are hunted & sexually tortured in the Denver area, local police & the FBI fear they have a violent serial rapist in their midst. Similar attacks occur across the country and pressure mounts to find this predator before he strikes again.
