The Baseline Killer

The Baseline Killer stalked his prey by cornering women as they went about their everyday lives: leaving work, washing a car, waiting at a bus stop.

An eight-year-old boy came home from school to find his mother dead in their apartment. Another woman was discovered under a pile of debris.

In February 2006, Romelia Vargas and Mirna Palma-Roman were attacked in the lunch truck they operated. Cops found them hours later in puddles of their own blood.

A month later, George Chou offered Liliana Sanchez-Cabrera a ride home after her first day at Yoshi's, the restaurant where they both worked. Chou's body was found in the alley out back; Sanchez-Cabrera's ended up in a deserted parking lot a mile away.

That's just part of the list. And, authorities say now, this list would have been much shorter if they hadn't made a major error in the investigation of a 2005 sexual assault.

In September of that year, a man attacked two sisters as they walked home through a South Phoenix park. The armed assailant pushed them into the bushes and ordered them to strip. The older sister was pregnant. The killer molested her, and forced her at gunpoint to watch as he raped the younger woman.

Phoenix police took two swabs from one of the women's breasts, hoping that lab tests would find DNA that would identify the attacker. One swab didn't show any of the perpetrator's DNA; the other swab was mishandled and not immediately tested with the first.