Before police confiscated her 487 cats, Ruth Knueven tried to hide some of the animals, moving them from her Mount Vernon home to her daughter's townhouse in Burke, unintentionally killing one in the process, according to court records.

Fairfax County police cited Knueven's reluctance to surrender her cats as the reason for wanting to search her daughter's townhouse. Armed with a warrant, police raided Karen Forrest's house Wednesday night, finding 38 adult cats, nine kittens and 134 dead felines.

The raid brought the number of cats taken from Knueven's possession to 487, including about 221 that were dead. Nearly all the cats were undomesticated and suffered from contagious respiratory problems, officials said. All but eight were euthanized.

While the case remains under investigation, Knueven, 82, has been charged with failing to care for and properly dispose of cats found in her Mount Vernon home, both misdemeanors.

Knueven also faces a misdemeanor charge of obstructing justice, police said, because she tampered with traps that animal control officers had set to round up the feral cats still hiding in her home. Police said Knueven's attempt to hide the cats resulted in the death of one of the animals, and they have charged her with cruelty to animals, another misdemeanor.

Police responded to Knueven's home last week when neighbors called to complain about strong cat odors.

In an interview Wednesday, Knueven talked openly about how she had surrendered her kitchen, family room and garage to her growing clutter of cats, explaining, "I got overwhelmed."

Investigators said the animals largely destroyed the kitchen plumbing, mangled the kitchen cabinets and blanketed the house with urine and excrement. County Health Department officials have ruled the home uninhabitable until Knueven makes repairs.

During the raid Wednesday night, animal control officers wore respirators to collect the cats inside Forrest's two-story brick townhouse. In all, they removed 53 large Rubbermaid containers holding cat carcasses, which they stacked inside a horse trailer.

Curious neighbors lingered outside in the dark to watch. Most were mindful to stay clear of the odors emanating from the home's open door. Police said the poor condition of the townhouse on Lakepointe Drive rivaled that of Knueven's own home. Health Department officials said they are investigating.

Neighbors said Knueven has been a fixture in the neighborhood for years, and many have often seen her taking what appeared to be trash bags in and out of her daughter's townhouse. Knueven and her husband live in the Mount Vernon house, and their daughter, Forrest, 57, apparently lives at both homes, according to the affidavit.

Becky Robinson, founder and national director of Alley Cat Allies, which advocates "humane and effective" methods to reduce feral cat populations, said Knueven's effort to help the cats was misguided.

"It's devastating to the community," Robinson said. "It's horrible suffering for the animals. It's a public health threat to the people, and what is it costing the taxpayers? We have to ask ourselves these very hard questions."

Knueven said she started collecting the strays in her neighborhood years ago to protect them from being hit by cars and shelter them from the elements.

Police first made a cat call to her home in August 2001 when they removed 120 felines, many of them Siamese. The condition of her home was not as bad, and officials let her keep five cats.

But neighbors complained again the following year about cat odors, and the Health Department was dispatched. Knueven was ordered to clean up cat waste inside her home and make repairs. The case was officially closed in November 2002.

Authorities said they did not know that Knueven was accumulating more animals until this month when a neighbor called to complain that the odor outside the house had become intolerable.

Each year, Fairfax gets two or three reports of animal collectors. Officials said that many -- but not all -- collectors, also known as hoarders, let their collections -- whether animals or tin cans or newspapers -- grow unchecked. Often, experts said, they suffer from some kind of mental illness.

Stephanie LaFarge is a clinical psychologist and director of counseling at the American Society for the Prevention of Cruelty to Animals in New York. She said it is "classic behavior" for hoarders to have recurrent episodes in which they accumulate animals and then keep the carcasses of those that have died.

"If it isn't cats they're focused on, then it's lids or plastic bags or newspapers," LeFarge said. "They'd have the same difficulty throwing those things out. It becomes impossible to weed through them. When it's newspapers and tin cans, you can say, 'Who cares.' But when the thing you're collecting also can suffer, then there's a victim . . . the animals."

Often, the only thing that keeps hoarders from repeating their behavior is the time-consuming checkups by animal control officers who make regular visits to their home, she said.

"That person knows they're coming back," LaFarge said. "It's like a drug addict having to give urine."

Staff writer Tom Jackman contributed to this report.

A cat lies in front of the Mount Vernon home where more than 300 were removed.