E1 - Pure Evil

Aired: September 09, 2012

The 1995 death of a Chicago woman whose body was found on a Wisconsin highway is detailed in the Season 4 premiere.

E2 - The Perfect Suspect

Aired: September 16, 2012

In Arkansas, three women are murdered over the course of three years.

E3 - Wolf in Sheep's Clothing

Aired: September 23, 2012

The 1995 murder of an 8-year-old girl sparks a manhunt for her killer.

E4 - Blood Trail

Aired: September 30, 2012

The 1999 slaying of a young woman in Germantown, Wis., is recalled.

E5 - Mother's Day Murders

Aired: October 07, 2012

The 1985 murders of a young military wife and two of her daughters are investigated.

E6 - Gruesome Discovery

Aired: October 14, 2012

Recalling the 1994 murder case of a young mother who was beaten and left in a garbage bin.

E7 - A Bike Ride to Murder

Aired: October 21, 2012

The 1991 murder of a young girl in San Diego is investigated.

E8 - Murder on the Menu

Aired: October 28, 2012

The 2004 murder and dismemberment of a chef is investigated.

E9 - Triple Threat

Aired: November 11, 2012

The 1993 strangling death of a young mother in California is probed.

E10 - City Under Siege

Aired: November 18, 2012

A look at the 2006 shooting death of a young nightclub worker in Scottsdale, Ariz.

E11 - Killings in Kentucky

Aired: November 25, 2012

A 1993 triple homicide results in the deaths of a Kentucky veterinarian and his family.

E12 - No Mercy

Aired: December 02, 2012

The 2001 strangling death of a mother of triplets in Puyallup, Wash., is investigated.

E13 - Maritime Murder

Aired: December 09, 2012

The 1982 poisoning death of a naval officer is investigated.