Body identified as Danielle van Dam

Pfingst said a nationally renowned forensic dentist identified Danielle's remains through dental records.

SAN DIEGO, California (CNN) -- A medical examiner confirmed Thursday that a body found in the desert near San Diego is that of Danielle van Dam, the 7-year-old girl who was reported missing February 2.

Dental records were used to positively identify the remains, San Diego County District Attorney Paul Pfingst said.

He told reporters at a news conference that due to the advanced state of decomposition of the body, the medical examiner had not yet been able to determine a cause of death.

San Diego Police Chief David Bejarano delivered the news to the girl's parents, Damon and Brenda van Dam, who remain in seclusion.

VIDEO Authorities in California say they believe they have found the body of 7-year-old Danielle Van Dam, who has been missing for more than three weeks (February 28) Play video (QuickTime, Real or Windows Media)

Pfingst thanked volunteers who aided the search for Danielle. He called their work "extraordinarily helpful."

"It has been one of the most extraordinary things I have seen in my years in law enforcement," he said. "Looking for the proverbial needle in a haystack, and by gosh, the searchers found it."

Police have charged a neighbor, David Westerfield, with murder and kidnapping in the girl's disappearance. In a court appearance Wednesday, Westerfield, 50, pleaded not guilty to those charges and to a charge of possession of child pornography.

Pfingst was asked whether tests had shown the girl had been assaulted before her death, but declined to answer.

Investigators say the body found had a necklace like the one Danielle was wearing the night she disappeared.

"I'm not going to speculate about that in the absence of evidence. It wouldn't be fair to the family and it would just be hypotheticals and guesswork," he said. "This is a sad day for a lot of people, and I don't want to engender speculation that would possibly make it even sadder."

Danielle's body was found Wednesday in a remote spot 25 miles east of San Diego. It was discovered about 25 to 30 feet from a two-lane road near a lake by a search group that has been working with the family since Danielle disappeared from her suburban San Diego home.

Pfingst said finding her remains would help him prosecute her alleged killer.

"Obviously, the more evidence one has, the better off a case is," he said.

San Diego police Lt. Jim Duncan earlier said investigators were going over the crime scene, near the city of El Cajon, "with a fine-toothed comb" looking for any evidence that could be linked to the missing girl. He said the state of decomposition indicated that the body was dumped shortly after the disappearance and that it had not been covered or hidden in any way.

A police photographer at the crime scene

Cadaver dogs were on the scene, he said, looking for any part of the remains that could have been separated from the body during a long stay in the open, and evidence collectors were taking plaster casts of tire tracks in the area. Later in the day, photographers planned to take aerial photographs of the crime scene.

Soon after the body was found, authorities said it matched the girl's description and that it had a plastic necklace similar to one Danielle was wearing on the night she disappeared and an earring matching one belonging to the girl.

Danielle was last seen February 1 when her father put her to bed about 10 p.m. She was discovered missing at 9 the following morning.

Westerfield, a self-employed engineer and twice-divorced father of two grown children, was arrested Friday after authorities said searches of his home and two seized vehicles turned up DNA matches with the girl's blood. Police also said they found other DNA evidence on an article of Danielle's clothing in her bedroom.