Modesto police said Wednesday that they believe Laci Peterson was the victim of a homicide.
"As the investigation has progressed, we have increasingly come to believe that Laci Peterson is the victim of a violent crime," said Detective Craig Grogan, lead investigator.
"This investigation began as a missing person case, and we all were hopeful that Laci would return home safely. However, we have come to consider this a homicide case."
Also Wednes-day, the Modesto-based Carole Sund-Carrington Memorial Reward Foundation announced a $50,000 reward for information that leads directly to the location and recovery of Peterson's body.
Kim Petersen, the foundation's executive director, said the money has been diverted from a $500,000 reward posted previously for Peterson's safe return. She said the money transfer has the approval of the people who funded the original reward.
Peterson, 27, was reported missing Dec. 24, when she was eight months pregnant; her due date passed in mid-February.
Her husband, Scott Peterson, 30, has not been eliminated as a suspect in the investigation, police say.
Police spokesman Doug Ridenour would not elaborate on why or when the missing person case became a homicide investigation.
"This hasn't really changed anything for us; it's only changed for (the media)," Ridenour said. "Investigators told me yesterday that the investigation is going well. We're confident this case will be resolved, and we're continuing in that direction."
He would not comment on a police visit to the path along the Delta-Mendota Canal where a private investigator said he found spilled concrete mix. The investigator, Bill Garcia, added that the mix appeared to be marked with the track of a trailer tire.
Garcia said he made the discovery on Monday and that police planned to take a look. A television news program showed videotape of police officers and Garcia examining the canal.
Ridenour said police did not ask Garcia to get involved in the case, but they have talked with him about his findings.
As Ridenour addressed an afternoon news conference, several of Laci Peterson's family members stood off to the side. They held hands and listened intently as he spoke, then left when reporters began asking Ridenour questions.
"Our family desperately needs to know where she is and what has happened to her," the family said in a statement read by Kim Petersen.
"We plead to the person or persons responsible for Laci's disappearance to dig deep within yourself, find the compassion for our family and provide the information necessary for her recovery."
Bee staff writer Ty Phillips can be reached at 578-2331 or firstname.lastname@example.org.