Some ask why no Amber Alert issued for missing Sandra Cantu

The murder of 8-year-old Sandra Cantu in Tracy, California, has brought America's Amber Alert program under the microscope. Sandra vanished in broad daylight on March 27.
Surveillance video from that afternoon showed her happily skipping to go play at her friend's house. After she failed to return home, her family alerted the authorities, but an Amber Alert was not issued. Ten days later, Sandra's body was found stuffed inside a piece of luggage in an irrigation ditch near her home. The frantic search for the killer may be over, as police arrested Melissa Huckaby on April 10 and charged her with murder.
http://www.cnn.com/2009/CRIME/04/21/velez.mitchell.amber/index.html