Prosecutors have dropped charges against a man accused in the deaths of dozens of ferrets after the woman who raised the furry creatures failed a lie-detector test.

Eight counts of first-degree animal cruelty were dropped after months of investigative work by police revealed discrepancies in ferret breeder Jean Smith's claims, Spokane County deputy prosecutor Michelle Lombardi said.Among other things, police found no witnesses who could verify Smith's account that she had spotted Lance A. Seurer inside her northeast Spokane home on Nov. 21, moments before she found the dead animals, Lombardi said.

Smith, 50, told police 93 animals had been killed, causing a net loss of more than $7,000 to her breeding business.

The attack sparked outrage among animal advocates. Smith received checks and donated supplies from as far as New Zealand for animals that survived the attack.

Investigators said the animals appeared to have been stabbed with a pointed object believed to be a syringe.

Seurer was arrested in December. At the time of the attack, the 20-year-old had been renting a room in Smith's home.

He pleaded not guilty and insisted he hadn't harmed the animals. A trial had been scheduled to start next month in Spokane County Superior Court.

Seurer's lawyer, Doug Phelps, said his client was relieved that charges were dropped.

"If you look at motive, my client had nothing to gain from doing this," Phelps said.

Last month, detectives requested Smith take a lie-detector test. On Wednesday, authorities cited the test results as the basis for dropping the charges.

The charges were dropped without prejudice, meaning they could be refiled if new evidence is found.

Smith was asked during the test whether she killed the ferrets. Lombardi declined to say how Smith answered or how the lie-detector machine rated her answer.

Another reason prosecutors cited for dropping the charges was confusion over how many ferrets died.

Smith claims 93 were killed, but police could only find 20 bodies, police detective Joe Walker said.

Smith on Wednesday urged police to continue investigating the crime.

Asked why police found only 20 dead ferrets, she said: "I know how many there were. I had the others disposed of."