FEASTERVILLE, Pa. -- Authorities returned Saturday to the Pennsylvania home where a man was living with a dozen girls, including one whose parents said they gave her to him because he helped them financially.

Officials in Bucks County, near Philadelphia, were acting on a tip Thursday when they found 51-year-old Lee Kaplan at his Feasterville home, along with 12 girls ranging in age from six months to 18 years.

The oldest girl told police that she and Kaplan have three-year-old and six-month-old children. Kaplan faces charges including statutory sexual assault, unlawful contact with a minor and aggravated indecent assault.

Lee Kaplan Lower Southampton Police Department via KYW-TV

Neighbor Jen Betz has been hailed as a hero for trusting the odd feeling she had about the house and calling a child welfare hotline, CBS Philadelphia station KYW reported.

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"I just made the call, I just, I don't know. It's just an instinct," Betz told the station.

"You notice these little children, these little girls -- only little girls -- and they be outside very rarely, very sporadically, you'd see one or two," Betz said.

Police said that when the neighbors inquired, Kaplan said he lived alone in the house with boarded-up windows and high weeds.

"They're so sad and fearful every time I see them. That's what made me call. I've been telling my husband for years 'Something isn't right, something isn't right,'" she said.

On Saturday, police and dogs scoured the home's backyard for evidence. Lt. Ted Krimmel of the Lower Southampton police department said authorities waited until dawn so they would be able to search the property in daylight.

"We have a search warrant for the entire property," he said. "There are dogs searching for evidence."

When police entered the home Thursday, "all the children were running around," Krimmel said. "Some were hiding. They were well-behaved, but scared."

"They were living down in the basement; they were hiding in the chicken coop," Lower Southampton director of public safety Robert Hoopes told KYW on Saturday.

District Attorney David Heckler said the parents of the girl Kaplan is accused of assaulting told police they were going to lose their farm until Kaplan "came out of the blue and saved them from financial ruin."

Krimmel said officials are trying to verify who the parents of the other children found at the home are. The teenager's parents told police the other nine girls in the house were their children, but no birth certificates or Social Security cards could be located to confirm that, he said.

"They haven't had a chance to talk with the children yet. And I am sure they want to find out were they abused, weren't they abused," Hoopes told KYW.

He told the station there were air mattresses, musical instruments and "tens of thousands of dollars of trains set up" in the basement, adding that the children may have been home-schooled.

The children are now together in protective custody, according to Heckler.

Authorities allege in an affidavit that the girl's father, Daniel Stoltzfus, told an officer he gave his 14-year-old daughter to Kaplan after researching the legality of such an action online. Stoltzfus is charged with conspiracy of statutory sexual assault and children endangerment. His wife, Savilla Stoltzfus, is charged with endangering the welfare of a child.

All three were being held in lieu of $1 million bail. Court documents don't list attorneys who could respond to the charges.

Heckler said the children apparently did not attend school and it was unclear if they had ever been to a doctor, but they didn't appear to be in bad health and showed no visible signs of trauma.

Another neighbor, Bob Greenfield, said Kaplan seemed "weird" and he now wishes that he also had called authorities.

"You knew something was wrong," he said. "It makes you feel bad. If I had said something a while ago, they would have come earlier."

The Philadelphia Inquirer reported that the Stoltzfuses were born into the Amish faith, but renounced it amid a long fight with community elders, according to a federal lawsuit they filed in 2009 against their former church. The lawsuit, which was dismissed later that year, said they operated a metalworking business on their property.