In July 2008, the mortgage fell into default. In August, Castellanos received a letter that appeared to be from her lender, telling her she could enroll in a free program to save her home. It even included a warning to beware of foreclosure rescue scams.
"I really fell for it," she said, adding that she responded immediately.
Days later, a man phoned Castellanos to say she and her husband had been approved for a more affordable loan, with delinquency fees tacked onto the end.
This sounded reasonable, Castellanos recalled, so she didn't question it when told to send her payments via money order or cashier's check to the "Payment Processing Department" at a postal box in North Hills.
But her bank had nothing to do with the purported new loan or the mail drop.
The California attorney general's office had been fielding complaints for months from homeowners who had fallen victim to what one prosecutor termed a "brilliant scheme."
Representatives of this operation allegedly induced homeowners to send them as many as three consecutive mortgage payments. More than $1 million flowed through a series of bank accounts, much of it eventually crossing the border to banks in Mexico, according to the attorney general's office.
In some cases, people lost their homes because they did nothing to head off foreclosure, believing they had made a deal with their bank.
Despite there being hundreds of victims, investigators found the trail confusing. The operation did not register its phone lines in its own name. Instead, investigators said, its 800-numbers ran through Internet phone companies. It was the same with the bank accounts.
Birch, Rosenau and a forensic auditor began working backward from the accounts where checks were deposited and postal boxes where victims sent their money.
They determined that much of the money seemed to go to Juan Jose Perez and Isuara Hernandez, a married couple with three children who had recently lived in San Bernardino County.
On Oct. 27, the attorney general's office filed a 39-count complaint charging Hernandez, Perez and several associates with grand theft, money-laundering and conspiracy. Five of Hernandez and Perez's associates pleaded guilty; but Hernandez and Perez, who authorities say are the ringleaders, have eluded capture.
Investigators suspect they went to Mexico.
On Oct. 29, the trail led to Anna Santos, 22, of North Hills.