Human remains were found Tuesday in a Moreno Valley neighborhood, but investigators could not immediately say whether the body was that of a 17-year-old girl who was abducted last week on her way to a friend's house.
Deputy Nelissa Nieburger said the identification of the body is "related" to the investigation into the disappearance of Norma Lopez. Her father told Spanish-language television station KMEX that the human remains are those of his daughter.
Sheriff's officials have scheduled a 2 p.m. news conference to discuss the case.
Local news from across Southern California
Late Tuesday night authorities declared the body decomposed and too far gone to even say whether it was male or female. An autopsy was scheduled for 9 a.m. Wednesday, but authorities have not released the results.
The family of Norma Lopez was in seclusion Tuesday night.
The body was found around 3 p.m., apparently by a resident, near Theodore Street and Dracaea Avenue. Investigators would not say whether the remains were of a male or female.
Norma Lopez disappeared Thursday morning after she finished a summer class at Valley View High School and took a shortcut across a field to a residence in the 27300 block of Cottonwood Avenue -- about three miles from the spot where the remains were found Tuesday.
A $35,000 reward was offered Tuesday for information leading to the girl's safe return.
During a news conference Tuesday morning at the Moreno Valley Police Department, 18-year-old Elizabeth Lopez pleaded for her sister's abductor to do the right thing.
"If the person that took her is out there, please let her go," Lopez said. "She hasn't done anything to deserve this. Please have a touch of heart and let her go. We'll be searching for her."
A green sport-utility vehicle was seen speeding away from the area around the time of her disappearance, but authorities have not been able to ascertain whether there's a connection.
"We're doing everything possible to find Norma," said Riverside County sheriff's Capt. John Anderson, who oversees the Moreno Valley police force. "This is a good family, and this is a good girl. Please keep calling in (with information)."
Los Angeles-based FBI Supervisory Special Agent Don Roberts said the agency was providing "significant resources" in the search.
"We're here every day and every night," he said. "We're not going anywhere until this case is solved. We're manufacturing new leads from contacts in the neighborhood, school associates, friends and people who knew Norma.
"This is a tragic scenario," he added. "Child abduction is every parent's worst fear, including my own ... We'll leave no stone unturned and no lead uncovered until we find an answer to this mystery. We all hope that it leads to the safe recovery of Norma."
Martin and Norma Lopez dismissed suggestions their daughter might have run away or left voluntarily.
"She is not a problem child," her mother said in Spanish. "If my child were a problem child, we wouldn't have all these people helping us."
Over the weekend, sheriff's deputies, joined by about 200 community members, scoured the local area, searching for any clues as to what might have happened to Norma.
Sheriff's Sgt. Joe Borja said the missing girl's belongings were found on the trail she was using, suggesting a struggle.
"It's unknown at this point how many suspects may have been involved, but we're following up every lead," Borja said.
According to the sergeant, residents should be alert to any statements or unusual behavior that could help with the investigation.
"If you know somebody who is acting peculiarly in a neighborhood, doing things that make you nervous, let us know," said Borja. "We're especially concerned with deviant behavior."
On Monday, a Moreno Valley resident, Mike Rios, who identified himself to a reporter as a city councilman, claimed there was a $7,500 reward for information on the teen's whereabouts.
Moreno Valley Mayor Bonnie Flickinger said Tuesday that Rios has never been a councilman, and authorities disavowed any knowledge of a reward other than the one offered Tuesday, which combines contributions from the city, the FBI and other donors.
Norma is about 5 feet 7 inches tall and 110 pounds. She was last seen wearing a black-and-white horizontal stripe sleeveless shirt, "skinny" jeans and black shoes, according to the sheriff's department.
Anyone with information on her whereabouts was urged to call (877) 242- 4345. Investigators are also inviting email tips at FindNorma@riversidesheriff.org.