(CNN) -- Two girls claiming they'd been held captive for several months or more in "filthy living conditions" told police they ran to a neighbor's house to escape their knife-wielding stepfather, according to a Tucson, Arizona, police report.
When police responded Tuesday just after 4 a.m. to a report of a domestic incident involving a knife, they found a third sister, a 17-year-old, locked in a bedroom, the report says.
Neighbors told CNN affiliates KTVK and KOLD that they didn't realize children lived at the residence.
"Upon arrival, officers contacted two juvenile females, ages 12 and 13, who had (run) to the neighbor's house alleging that their stepfather had attempted to break into their bedroom while brandishing a knife," the incident report said.
"During the course of the investigation, it was alleged by the girls that they had been imprisoned in their bedrooms for at least the last several months and possibly up to two years."
The girls were "extremely dirty" and told police they hadn't bathed in at least four months, the report said.
"They were kept in filthy living conditions and allegedly only being fed once a day," it added.
The neighbors to whose house the girls ran asked not to be identified and told KTVK that they had lived there since August and never seen children.
One of the neighbors said the girls "were distraught and visibly shaken. ... They didn't have any shoes on, and they looked like they had just gotten out of bed."
A woman who has lived in the neighborhood for five years told KOLD she wasn't aware anyone lived in the house and hadn't seen any visible activity there.
Another neighbor told KOLD, "If there were kids, they never came out and played. We have kids all over this neighborhood and they had to try extra hard to keep themselves secluded because obviously somebody would have said, noticed something."
The stepfather, Fernando Richter, 34, and the mother, Sophia Richter, 32, were arrested and booked into the Pima County Jail.
Sophia Richter faces three counts of kidnapping, three counts of child abuse/emotional abuse and three counts of child abuse/physical abuse. The stepfather faces the same charges, plus an additional count of sexual abuse with a person younger than 15, according to the report.