Preliminary autopsy results indicate the woman died of asphyxiation and head injuries from being strangled while dragged by a vehicle, according to sheriff's spokeswoman Kim Castellano. Toxicology results could take three weeks.
Neighbors discovered the woman's body at about 2:30 a.m. Monday in Surrey Ridge, an upscale neighborhood near Castle Rock, Colo., about 20 miles south of Denver.
Police say investigators detained several witnesses for questioning but no one has been arrested or identified as a possible suspect.
Authorities say a photo of an unidentified couple was found near the body of the murdered woman, but investigators did not know whether the picture has any connection to the victim or the crime.
Police appealing to the public for help in identifying the victim and the individuals in the photo say the victim is white, about five feet tall, in her mid 30s, with shoulder length red hair, hazel or green eyes, with a stocky build, weighing about 130 to 140 pounds.
Nancy Foley, who lives next door to the house where the body was found, says the victim had an orange tow rope around her neck and her face was unrecognizable.
"I was trying to sleep last night, thinking about how this poor lady was dragged, treated worse than an animal," Foley said. "She was really mangled."
A witness says the victim's clothing was shredded.
Investigators are checking missing persons reports for possible clues.
In an interview with CBS News station KCNC-TV, Douglas County Sheriff's Officer Tony Spurlock says the victim is not believed to have lived in the neighborhood where she was found.
"Obviously, she was brought here to this location," said Spurlock, "because we don't have another car here that was left abandoned. It's hard to tell what the motive is at this point."
Authorities have stepped up patrols in the usually quiet neighborhood, and residents are locking their doors at night.
"It's a very safe neighborhood, or it has been, anyway," said Foley.
The blood was cleaned off the paved road, but traces remained, upsetting neighbors.
"We don't want to attract any more attention than what we're already getting. This is our little piece of heaven," Foley said.