The FBI has 50 agents working the Ridgeway investigation and they are asking the public to help them catch whoever is responsible.
Officers spent most of the day at the Pattridge open space and reopened the Leyden Road to traffic Thursday evening.
The person chose an isolated area, crossed under the barbed wire fence at a drainage culvert, and left the body on a hillside. It's still not confirmed if the body is Jessica's.
The FBI knows from experience, the best leads will likely come from people at home who have a hunch and make the call.
"We suspect that somebody in the community knows this individual," Denver FBI spokesman Dave Joly said.
Joly says you need to focus, not on how this person looks, but how they act.
"Any kind if unusual behavior between last Friday and today," Joly said.
That behavior could include missing work and appointments, leaving town, changes in alcohol and drug use, or even changes in appearance.
"Somebody who is very engaged in the media coverage of the investigation and maybe they're a little annoyed by all the coverage," Joly said.
Former FBI profiler Clint Van Zandt says the condition of the body, which was described by Westminster police spokesman Trevor Materasso as "not intact," indicates an experienced killer.
"And if it is such a person who would do such a grisly act, it is someone who is fully capable of doing this again. And not withstanding investigators are racing against the clock to try to find the offender, before he or she might strike again," Van Zandt said.
The FBI assumes the person they're looking for is a male, as statistics show that is most likely the case.
"It could be your boss; it could be your friend, and ultimately it could be your family member," Van Zandt said.
Investigators have received more than 1,200 tips so far.
If you suspect anything, no matter how insignificant you think it may be, the FBI wants you to call 303-658-4336.
(KUSA-TV © 2012 Multimedia Holdings Corporation)