A Crystal woman is accused of hoarding 124 cats in a home that has since been boarded up after being found unfit for habitation. Meanwhile, nine of the cats with severe upper respiratory infections were euthanized.

Shawna Maria Duffy, 47, faces 10 felony counts of animal mistreatment, according to charges filed Monday in Hennepin County District Court. Her first court appearance is scheduled for April 30. An attorney for her is not yet listed, and Duffy did not return phone calls.

The Animal Humane Society and law enforcement began investigating Duffy following reports of illegal animal waste dumping in neighboring Plymouth along Bass Lake Road.

Plymouth resident Carolyn Marinan began noticing a pattern of feces-filled garbage bags being left on the roadway last summer. She typically picks up litter while she walks, but these bags were too hefty and smelly. So she notified Hennepin County, where she works as a spokesperson, and crews in the transportation department responded diligently.

Marinan said she realized it wasn’t the biggest issue in the world, but she couldn’t let it go and kept sending photos of the recurring trash to police, who later assigned a detective to the case. They set up a camera and license plate reader to identify the suspect. A man, not identified in the criminal complaint, admitted to dumping the bags from his girlfriend’s house, charges state.

“I’m just astounded by the work they did and the dedication to find this person, which led to a much bigger discovery, sadly,” Marinan said.

Police went to Duffy’s home Feb. 2. Officers didn’t find her, but they heard numerous animals inside and were “met by a very strong odor of cat feces/urine” while standing 10 to 15 feet away from the front door, charges state.

Animal control returned a few weeks later. Again, Duffy wasn’t home. They didn’t meet her until executing a search warrant at the end of February, when they recovered 96 cats and kittens. Officers also located one cat skull and noted that “the air was thick with ammonia,” according to charges.

“Every surface of the inside floors, walls and any furniture were coated with mud-like substances determined to be dried cat feces and vomit,” charges continued. All the litter boxes were full. Cats were found in the crawl space under the main floor, and some were inaccessible because they had climbed into holes in the walls and into furnace vents.

Officials returned four more times in March to continue removing cats from the home that city inspectors determined was unfit to live in.

Only one bowl of water was left in the kitchen sink, filled by a continuous drip, and a medium-sized plastic tote bin of food was let open for 124 cats to eat. All the cats were dehydrated and malnourished. About 70% were underweight.

The Humane Society, headquartered in Golden Valley, conducted forensic exams on the cats in the most severe conditions. The veterinary findings note that all 124 cats had upper respiratory infections with the majority having severe infections.

Most of the cats are unsocial, which presents barriers in rehoming.

Dr. Graham Brayshaw, director of veterinary medicine at the Humane Society, said all the surviving cats are at the Golden Valley shelter.

He said the organization doesn’t celebrate cases like this, but securing gross misdemeanor and felony charges ensures that a defendant who is found guilty has mandated mental health follow-ups.

“I’m not worried about just this group of cats, but a potential next group of cats because hoarding has a 100% recidivism rate,” he said. “We want to make sure the next cats are protected and taken care of, and get the person the help they need.”

He said hoarders often are blind to the suffering they are inflicting on animals. But once confronted with the severity of the problem, Duffy willingly signed the cats over to the Humane Society, avoiding a potential legal battle. Brayshaw said that with cats, a dozen can quickly escalate to something unmanageable.

“If you look at any county in Minnesota, I would be very surprised if you couldn’t find at least a couple houses that are similar to this,” Brayshaw said. “This was definitely worse than most.”

Just last week, a St. Cloud animal shelter took in 94 cats that the Minnesota Federated Humane Societiesremoved from a home in Crosby. Police executed a search warrant April 11, recovering the surviving cats while eight were found dead.

Brayshaw said there has been an uptick in these cases, but they tend to pop up seasonally: in the spring, when people start to smell what they couldn’t over winter, and in the fall, when people report worries about animals freezing in the cold.

The Animal Humane Society accepts reports about suspected animal abuse, mistreatment, neglect and hoarding by phone at 952-435-7738 or online at animalhumanesociety.org.

“It’s not that different than thinking of any other crime or social worry. It’s usually not a cop out there trying to catch everything when it’s happening,” Brayshaw said. “It’s usually a report that comes in.”