DENVER - Hundreds are set to attend a public memorial service Tuesday for a 10-year-old Colorado girl as the search for her abductor continues.
Multiple agencies are checking every lead and asking for more tips from the public in their hunt for the killer of Jessica Ridgeway, a fifth-grader who was abducted Oct. 5 on her way to school in suburban Denver.
Cases like this -- in which a child apparently is abducted and killed by a stranger -- are "the ones that shock entire communities and scare us all," said Robert Lowery, senior executive director of the missing children's division at the National Center For Missing and Exploited Children.
Authorities have been tight-lipped about the investigation since they announced Friday that a body found on the edge of town belonged to Jessica.
The girl was last seen alive walking down a quiet street in her modest Westminster neighborhood. Her school backpack was found three days later in Superior, another Denver suburb about 7 miles northwest of her home.
Jessica's body was found Wednesday, the same day authorities ruled out her parents as suspects. The body was found along a remote road that locals say few knew about.
Authorities usually are reserved in what they say to the public in such cases, out of concern for causing unnecessary alarm. They issued a statement last week advising residents to be suspicious of their bosses, friends and family members.
Authorities asked the public to keep an eye out for people exhibiting unusual behaviors -- like leaving town unexpectedly, missing appointments, consuming unusual amounts of alcohol or changing their appearance. The idea was that the killer would not be able to act normally after committing the crime.
"They may have no suspects," said Kenneth Lanning, a retired FBI behavior analyst in Fredericksburg, Va., who is now a consultant specializing in crimes against children. "But likely at this point, they have so many suspects and now they're trying to sort through them."
Lanning is not involved in the Colorado case but described such investigations as multi-track efforts, with volunteers and deputies searching homes, bushes, drainages and open space near the child's house while investigators develop a criminal case.
Police likely are pouring through hours of surveillance video taken at banks, gas stations, government buildings and elsewhere, Lanning said.
In Cody, Wyo., where an 11-year-old girl was abducted and sexually assaulted Oct. 8, police were able to get a license plate number from surveillance video at Yellowstone National Park that led them to a suspect in Montana. The girl was released hours after her abduction.
Investigators also have statistical data based on past crimes of this type that could provide a general profile of who may have committed the crime, Lanning and FBI profiler Clinton Van Zandt said.
Neither Lanning nor Van Zandt would provide an opinion on the Colorado case, saying each case is unique.
However, a 2006 report funded by the U.S. Department of Justice and compiled by Washington state Attorney General Rob McKenna determined the majority of suspects in such cases are single and between 18 and 30 years old.
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.
"We have all the stereotypes of some kind of ghoul who does this thing, a hunchback, pocked-marked face and lurks in the shadows," Lanning said. "Don't just call in about the evil nut job. Call in about the guy who appears normal."
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 also will analyze the evidence to build a suspect profile and a criminal case. 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 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 had been issued.