Farmworkers draining the irrigation pond found the suitcase containing SandraCantu's body, Tracy Police Chief Janet Thiessen said at an evening news conference.
Thiessen said the 8-year-old was wearing the same clothes she wore when last seenon March 27: a pink "Hello Kitty" T-shirt and black leggings.
Authorities planned an autopsy to determine the cause of death.
"Our heartfelt sympathies go to Sandra's family and friends," she said. "We willdetermine the person or persons responsible for this reprehensible act, and we will bring them tojustice."
Sandra's disappearance sparked a massive search effort around Tracy, about 60 mileseast of San Francisco, that included hundreds of volunteers and law enforcement officials,including the FBI, and more than 1,000 tips.
Before the evening's dramatic announcement, investigators cordoned off the areasurrounding the pond for hours and combed it for clues, as television trucks and reporters gatheredin the flat farmland nearby.
Police had been to the pond earlier in their search efforts, but it was full ofwater, Police Sgt. Tony Sheneman said.
"This is an unimaginable loss for any parent," he said.
Dozens of mourners - some holding candles, others wiping away tears - gatheredoutside the mobile home park where Sandra's family lives and she was last seen, as police blockedthe entrance.
"I am still in shock," said Brandy Robles, 27, who held her 2-year-old son. "You see this in themovies. I never thought it would be real life - real to me."
