It's been days since anyone has seen Sandra Cantu, an outgoing second-grader who went to visit a friend on Friday and never made it home.
The 8-year-old's family and police have launched a massive search in the area in and around the Orchard Estates Mobile Home Park in Tracy, Calif., reviewing surveillance footage and re-examining a disturbing encounter Sandra had with an older man nearly two years ago.
"She's very bubbly and friendly and we just want her to come home," Sandra's aunt, Angie Chavez told ABCNews.com.
Chavez said her niece, who lived with her mother, grandparents and three older siblings, had played at a friend's house in the park after school on Friday before coming home to check in around 4 p.m.
She told her family she was heading over to another friend's house. That was the last time she was seen.
"She usually checks in with her mom," Chavez said. "It was dinnertime ... and she wasn't here."
Video from a surveillance camera outside the family's house showed Sandra walking away from her home, also away from the only exit to the mobile home park. Chavez said the family learned later that the friend Sandra set out to visit wasn't home at the time.
Last seen wearing a Hello Kitty shirt and black leggings, Sandra has long, light brown hair with golden highlights from spending a lot of time out in the sun, her family said. Chavez described Sandra as a little girl who is very talkative, would make friends wherever she'd go and was always eager to help.
Chavez said Sandra would have never run off and knows better than that.
"She's always been told not to go outside the mobile home park," she said. "And she never has."
Chavez said Sandra's mother, her sister-in-law, is "very distraught."
"It's really difficult for her," she said.
The Federal Bureau of Investigation's Sacramento office confirmed that they are assisting police in Tracy, but deferred all questions to local police.
Tracy police Sgt. Tony Sheneman said police got a 911 call from the family at 7:53 p.m. Friday. Police initially searched her home and then expanded their efforts to the entire park when they couldn't find her, he said.
Over the course of the weekend, dogs, equestrian teams, ATVs and a helicopter from the California Highway Patrol were brought in to search for Sandra in the town of 81,000 residents 70 miles south of Sacramento.
"Every dog team we could find was brought in," Sheneman said.
Divers were also brought in to search a river, miles from her home, but found nothing, he said.
Chavez said the children at the park would often play at one another's homes and also in the park's open spaces, including a basketball court and a pool.
It was at that pool in the summer of 2007 that the Chavezes placed a call to police that is now being looked at more carefully. A man, Chavez said, made an inappropriate move with the little girl in plain sight.
"My mother-in-law saw him march over, sweep her hair off her face and give her a kiss on the lips," Chavez said, adding that the man was an Orchard Estates resident who still lives in the park.
Sheneman said he found out about the neighbor's kiss on Saturday. The neighbor is a man in his 60s who is still a resident of the park.
"He has been interviewed and may be interviewd again," Sheneman said, but he also noted that all residents of the park have been interviewed.
Chavez said she has always known Orchard Estates to be a family-friendly place that is safe for children.
Orchard Estates manager Marilyn Zuniga agreed, telling ABC News that "this is a very nice park" with about 100 homes.
"It's always been a very safe park," she said.
In addition to local police and the FBI, the National Center for Missing and Exploited Children has a team of retired law enforcement professionals, part of a program called "Team Adam," in Tracy helping both law enforcement and Sandra's family.
"The good news is, while few people believe it, most come home safely," the center's president, Ernie Allen, said of the 58,000 children who are reported missing annually.
Hoping to Bring Sandra Home
The Carole Sund-Carrington Foundation announced a $5,000 reward Monday to find Sandra, which is in addition to a $2,000 reward offered by the FBI and Trace Crime Stoppers for information concerning Sandra's whereabouts.
Two candelight vigils were held for Sandra, on Saturday and Sunday.
Sheneman said 230 professional search and rescue volunteers representing 16 government and emergency entities took part in the search over the weekend. They went house to house looking for the little girl, he said.
The Tracy police and the FBI are offering a $2,000 reward for any information in Sandra's disappearance.