As the FBI joined the search for a missing 12-year-old Vermont girl, state police on Friday released a surveillance video believed to show footage of one of the last glimses of Brooke Bennett before her disappearance.

State troopers had previously refrained from publicizing the footage from a security camera inside the Cumberland Farms store, where Brooke said she was meeting a female friend.

The tape shows the girl and her uncle walk into the shop, go to the register to buy something and then leave, each going in separate directions, with Brooke apparently walking away by herself.

She was seen about 45 minutes later inside the Randolph Village Laundromat, police said.

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Baker wouldn't say whether she was alone at that point, nor would he say whether police suspect foul play.

Also Friday, a team of police divers searched Sunset Lake and a popular teen hangout known as the Floating Bridge, near where a relative of Brooke's discovered some of her clothes a day earlier.

Police haven't identified any suspects in the child's disappearance, which prompted Vermont's first-ever Amber Alert.

Col. James Baker, director of Vermont State Police, said Friday that investigators aren't ruling out the possibility that Brooke may now be out of state.

Vermont state troopers told reporters that there had been sightings of Brooke and numerous phone tips had come in. They urged anyone who might have seen the girl to call state police.

Investigators from the Vermont State Police, FBI and other agencies were trying to track Brooke's movements after she was dropped off by her uncle and cousin.

The FBI, which had assigned two agents to the case Thursday, plans to send a five-person team made up of agents who specialize in child abduction cases, police said.

A major focus of the investigation was centered on her online activities.

"As we all know, warnings have gone out countless times, in this world that we live in today, there are folks that visit places, social networking spaces such as MySpace, whose intentions are not good. And they come from far away," said Baker.

Police want to hear from anyone who was in Randolph on Wednesday between 9:45 a.m. and 11 a.m., even if they don't think they saw anything, Baker said.

The girl was reported missing around 9 p.m. Wednesday after her uncle dropped her off at a convenience store about 12 hours earlier in Randolph, where she'd said she was going to meet a girlfriend to visit the friend's sick relative in the hospital.

But police believe that Brooke fibbed and may have been bound for a meeting with an unknown person whom she'd been communicating with on the social networking site MySpace.com.

Her dad asked for anyone with information about Brooke to come forward.

"Obviously, I'm upset," said James Bennett, choking back tears. "We just want her home. ... Help us find her."

Authorities haven't identified the person she was communicating with, but state police computer experts were analyzing the computer in a bid to learn more. They don't know if it was a woman or a man.

The girl established her first MySpace account under her father's supervision, but he later pulled the plug on it a couple of months ago after they learned about some of her activity on it, according to Bennett, 41, of Bethel, Vt.

"We told her when we set it up there that's things you're not gonna' do," he said. "We had a little respect problem after a month or so, so we shut it off. There was an issue, and we decided it was not appropriate for her to have it. We changed the password so she couldn't use it," he said.

She later set up an account from another computer, which Bennett said he didn't know until a week ago. The girl lives with her mother in Braintree, not with Bennett.

Brooke told family members that she was going to see a friend's sick relative at Dartmouth-Hitchcock Medical Center, in Lebanon, N.H., according to Vermont State Police Capt. David Covell.

"It is the family members' opinion that that was a ruse to the family to get to that location," said Covell. "There's been no interview conducted that supported that that was a legitimate meeting."

A family member searching for her Thursday in Brookfield — near her uncle's home, where she spent the night — found items belonging to her near Route 65 that were similar to what she had been wearing, prompting an intensive search by police and dogs in the area of the Floating Bridge, a popular hangout among local teens.

In the Amber Alert, police said they had no information about a suspect or any vehicle.

On Thursday, New England K-9 units searched the area around the bridge. Nothing of significance was found.

The girl, who just finished seventh grade, is described as 4-foot-11 inches tall, 98 pounds, wearing blue jeans, a pink sweater and white sneakers with pink lettering. She has blue eyes, brown hair with purple highlights and has pierced ears "top and bottom," according to the Amber Alert.

At the Randolph convenience store, a flier with a black-and-white photo of Brooke was taped to the glass door in front, and clerks handed out copies of it to customers inside. A store manager there declined comment on the girl's disappearance.

"It is certainly our hope that Miss Bennett is out there and has just failed for whatever reason to contact family and friends," said Covell. "At this point, we're looking at all possibilities."

Amber Alerts, which are named for Amber Hagerman, a 9-year-old Texas girl slain in 1996, are a partnership between law enforcement agencies, broadcasters, transportation agencies and the wireless industry to alert the public in the most serious child-abduction cases.

MySpace.com, the Web's most popular social networking site, has more than 110 million active users. It's a free site, but registration is required.

Anyone with information about Brooke's whereabouts is asked to call the state police at 802-234-9933.

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The Associated Press contributed to this report.