The study looked at more than 800 cases from 1968 to 2002, the latest figures available. It found nearly half the suspects were unemployed, and those who did have jobs worked in unskilled or semi-skilled labor occupations.
The report also said 21 percent of victims were 10 to 12 years old and initially encountered their abductor within a quarter-mile of their home. Jessica was 10 and last seen within two blocks of her house.
Lanning and Van Zandt noted investigators will build their own suspect profile using the evidence. They'll consider where Jessica was last seen alive and where her body was found, along with the condition of her body, which police have said was ‘‘not intact.’’ There’s also the girl’s backpack, which might contain clues.
‘‘Behavior can be expressed in a crime scene,’’ Lanning said. ‘‘We’re greatly hoping that in addition to behavioral clues, how about he left his DNA?’’
Lowery, of the National Center For Missing and Exploited Children, added that fewer children have been abducted and killed in recent years because of greater awareness and the Amber Alert system established nationwide in 2003. He said several abductors have released children after seeing or hearing such an alert.
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