STANTON, Calif. -- A kidnapped 5-year-old girl was sexually assaulted and suffocated before her nude body was dumped near a rural road in what investigators said Wednesday was a "calling card" from the killer warning that he intends to strike again.
Orange County Sheriff Mike Carona said Samantha Runnion was asphyxiated sometime Tuesday, though he didn't say how she was killed.
Autopsy results showed she was alive for hours after her abduction Monday evening. The sheriff also said Samantha may have fought against her killer and inflicted "injuries to his hands, arms and possibly face."
"Don't sleep, don't eat, because we're coming after you," Carona warned the killer in a televised news conference near the girl's home in Stanton.
Authorities said there was no prime suspect, and Carona warned parents in the area to tell their children to stay away from strangers. Samantha's abductor was described by police as a Hispanic man with slicked-back black hair and a thin, black mustache.
"We believe that he is a serial rapist and perhaps a serial killer and would strike again," the sheriff said.
The news spread fear in Stanton, a city of 38,000 southeast of Los Angeles.
Tammie Fike, 31, clutched the hand of her 6-year-old son, Anthony, as she headed to a memorial to say a prayer for Samantha. "I'm scared to let him go out," said Fike, who instructed her son to yell "fire" and to run if a stranger approached him.
"I'm only allowed to talk to friends of my mom," Anthony said.
Samantha's 27-year-old mother, Erin Runnion, who made an anguished plea for the return of her daughter a day earlier, remained in seclusion Wednesday.
Samantha's body was discovered Tuesday afternoon, less than 24 hours and about 50 miles from where she was abducted kicking and screaming outside her apartment building by a man who pulled up in a light green Honda or Acura car and asked for help finding his puppy. Samantha was playing with a 5-year-old friend at the time.
The abduction was at least the third high-profile disappearance of a child in the United States this year. Seven-year-old Danielle van Dam of San Diego was found dead, and a neighbor is on trial.
Fourteen-year-old Elizabeth Smart of Salt Lake City has been missing since June 5.