It shows Sandra Cantu skipping near the mobile home park where she lives, reports CBS News correspondent John Blackstone. Authorities say it was taken on March 27, the same day Sandra went missing after leaving home to play with a friend.
Hundreds of volunteers have combed the city's neighborhoods looking for Sandra, even replacing fliers with an updated photo of the girl with lighter hair.
On Sunday, Tracy police announced that ground searches would be scaled back as investigators focused on some of the more than 1,000 leads they've received.
"Until we have specific information that can lead us to whereabouts or information that would lead us to her whereabouts," said Sgt. Tony Sheneman, "we're going to hold off and concentrate when we get that."
Sandra's disappearance has been categorized as a missing persons case, Blackstone notes.
While police haven't said whether they believe she was abducted, Sandra's mother believes her daughter wouldn't have wandered off on her own. "I think somebody took her," a tearful Maria Chavez told reporters. "Somebody has her, because she wouldn't walk off. She wouldn't leave the mobile home park at all. I think somebody has her. Maybe somebody she knew?"
A $26,000 reward is being offered for information leading to Sandra's whereabouts.