What began as a desperate search in Colorado for 10-year-old Jessica Ridgeway has now turned into the hunt for a possible suspect with the release of a behavioral profile of the killer.
Police believe that the body found this week in Arvada, Colo., seven miles from where she disappeared is Jessica's.
The suspect is likely male and might have recently missed work or suddenly left town, according to the FBI's Behavioral Analysis Unit. The suspect might have already changed his appearance and gotten rid of his car.
"It could be your boss, it could be your friend and, ultimately, it could be your family member," FBI spokesman David Joly said.
The FBI is asking for the public's help locating the suspect, who might have been a "no show" and missed work immediately after the incident and offered a plausible excuse such as illness, death in the family or car trouble.
The individual might express an intense interest in the status of the investigation and pay close attention to the media. But some offenders might quickly turn off media accounts or try to redirect conversations concerning the victims or their families, according to the FBI.
Joly said the public should be looking for "abnormal behavior."
Investigators are now focusing on cellphone towers near Jessica's Westminster, Colo., home, where her backpack was found and where the remains were discovered in Arvada, Colo. If a phone number registers at all three towers, it could lead to a suspect.
Hundreds of officers continue to search fields, ravines and neighborhoods today near the park in Arvada where the body was found Wednesday night, seven miles from where Ridgeway disappeared last Friday.
Police haven't officially tied the crime scene at the Pattridge Park open space to the missing girl. But several law enforcement sources tell ABC News they believe the remains belong to Jessica. An announcement of a positive identification is expected today.
The condition of the body is delaying identification because the boy was "not intact," police said Thursday.
"This is extending the length of time it's taking for investigators to positively identify who that body is," Westminster Police Department spokesman Trevor Materasso said during a news conference.
Materasso said authorities expect to have a news conference later today to release more information.
Police were alerted to the body Wednesday night hours after they said that Ridgeway's parents were not suspects in her disappearance.
Ridgeway's mother, Sarah, told police she last saw her daughter in Westminster, Colo., Friday morning when Jessica left for school. The fifth-grader never showed up at a nearby park where she was supposed to meet friends for the one-mile walk to her elementary school. It was a route she took every day, but this time she never arrived.
The school called to report Jessica absent, but Sarah Ridgeway told police she was asleep during the day because she works overnights and did not get the call until eight hours later, when she called police.
ABC News' Christina Ng contributed to this report.