An abusive husband goes on the lam in the mountains after he allegedly murders his wife and their two children in their home.

A former soldier escapes custody after being caught with child pornography, and an accused child molester shoots it out with police.

After brutally slaying his entire family and torching their bodies, a former diplomat flees overseas, where he eludes authorities for decades.

A troubled ex-Marine fires on police and vanishes into the woods without a trace, and a drunk driver removes his tracking device and vanishes.

A trusted neighbor disappears after facing multiple charges of child molestation, and new evidence in an old case leads to a manhunt for the suspect.

Suspected of letting 11 undocumented immigrants perish in an overheated rail car, an accused human trafficker goes on the run from authorities.

The leader of a small cult flees overseas after he's accused of sexually abusing the underage daughters of many of his followers.

Parents of an abducted boy keep the search for their son alive after more than two decades, and a mother abducts her own daughter and hides her for more than a decade.

Season 2 begins with John Walsh providing updates on Season 1 fugitives who are still at large. Also: a recap of captured suspects and closed cases.

An oppressive, overbearing father is accused of murdering his high school-age daughters when they start dating boys their own age against his wishes.

A serially abusive stepfather is accused of sexually assaulting his stepdaughter for 15 years; a young police officer is accused of murdering his wife and molesting a 9-year-old student.

Two brothers kidnap and torture prostitutes, until one victim escapes and leads police to their house of horrors.

A young mother vanishes with her 2-year-old daughter; a serial child molester is caught in Texas, but flees his trial and begins his monstrous pattern again.

The religious leader of a Hindu community in Texas flees after being convicted of sexually abusing the children of his followers.

A woman hires a man to beat her estranged husband to death; a serial molester in Oregon abducts two women at knifepoint.

A report on a young father who allegedly murdered his parents in a haze of rage and drug addiction, abandoned his child and then fled to the American South.

Herberto Maldonado allegedly takes Lori Meija's life into a deadly downward spiral. After being accused of molesting a friend's 10-year-old daughter, Bruce Sawhill runs and sets into motion a tragic chain of events leading to a girl's death.

A mother kills herself and her son disappears. A man allegedly kills four members of his ex-girlfriend's family.

Season 3 begins with John Walsh offering updates on fugitives still at large and those who have been captured, resulting in closed cases.

Authorities in Texas are searching for William Joseph Greer who confessed to having murdered his girlfriend Tammy Esquivel, a divorced stripper in 2006, but has managed to stay one step ahead of the law.

Accounts of a Nebraskan alleged serial rapist and two members of the L.A. Boyz gang, brothers, who may be hiding in Mexico.

A search for Jorge Rueda Landeros, who is wanted in connection with the 2010 murder of American University accounting professor Sue Ann Marcum.

A search for Elby Hars, who allegedly abused a young girl in Columbia, S.C.; a hunt for Eugene Palmer, who allegedly shot and killed his daughter-in-law.

Police hunt Robert William Fisher who is wanted for the 2001 murders of his wife Mary and their two children; police pursue Honolulu couple John and Julieanne Dimitrion who are wanted for mortgage fraud.

Authorities in Harris County, Texas are desperate to find Alfonso Diaz-Juarez, a convicted pimp, child molester and sexual predator, known for profiting from prostitution and sex trade trafficking.

A Texas woman, Jennifer Puente, is being sought in connection with the horrific and brutal murder of her best friend in 2012, and already her accomplice/boyfriend is serving 34 years for his part in the crime.

A search for Anthony Burroughs who is wanted for a 2000 murder in Arizona; a hunt for William Jordan who was convicted of a 1974 murder in Georgia but then escaped from prison in 1984.

A serial child molester preys on young women in his own family for two generations, then vanishes just before his 12-year-old daughter is about testify at his trial.