SAN DIEGO -- Volunteers and members of the sheriff's search and rescue team combed an area near Poway over the weekend for 7-year-old Danielle van Dam, who was last seen in her Sabre Springs home 17 days ago.

Video

Danielle van Dam Video Montage

MISSING Danielle van Dam 4 feet tall, 58 pounds Blue eyes, dirty blond hair Possibly wearing blue pajamas INFORMATION (619) 531-2000 Danielle Missing Flyer DISCUSSION Share your feelings, thoughts for van Dam family

Danielle's parents, Damon and Brenda van Dam, spoke with reporters Monday morning, asking the public for help finding their daughter.

Danielle was last seen Feb. 1 when Damon put her to bed. She was discovered missing the next morning.

A neighbor of the van Dams, David Westerfield, has come under close scrutiny. Investigators have searched his home and impounded his sport utility vehicle and motor home.

Westerfield reportedly has provided a DNA sample for analysis.

On Wednesday, detectives conducted a third search of Westerfield's house -- two doors down from the van Dam home -- and carted away more boxes and bags of what they called "potential evidence."

Police have refused to disclose what they may have been looking for or what they found in the home of the 50-year-old design engineer.

Westerfield has also been under 24-hour surveillance.

Authorities refuse to call Westerfield anything more than a "potential suspect" and have not taken him into custody.

In one of his few public statements, Westerfield told reporters he spent the weekend Danielle went missing in the desert.

That prompted a search of the remote Imperial Valley area where Westerfield said he was.

Authorities have acknowledged that the odds of finding the girl alive are waning.

"We are not real hopeful on her condition," San Diego police homicide Lt. Jim Duncan told reporters several days ago.

Rewards offered in the case now total $185,000. Some are offered for her safe return. Others are payable in the event of an arrest and conviction.