It didn't belong to a dead aunt of Anna Ayala, who made the claim. Nor was the owner a woman who got too friendly with her pet leopard.
The finger came from a man who lost it in an industrial accident and gave it to the husband of Ayala, who allegedly planted it in a scam to get money.
"The puzzle pieces are beginning to fall into place, and the truth is being exposed," police Chief Rob Davis said at a news conference Friday.
Davis said a tip was called in to a hot line established by the Ohio-based fast-food chain, and police found the man in Nevada this week. He said scientific tests confirmed the finger was his.
Investigators had initially believed the 1½-inch fragment was a woman's because the nail was well-trimmed.
Davis would not identify the man or say why they think he gave the finger to Ayala's husband. The nature of the industrial accident was also not disclosed. They said only that the man was an associate of Ayala's husband, a construction worker.
Authorities said last month that they believed the story was a hoax, and they arrested Ayala at her home in Las Vegas and charged her with attempted grand larceny for allegedly trying to shake down Wendy's.
Ayala, 39, filed a claim against the restaurant chain shortly afterward, but later withdrew it as she came under scrutiny. Investigators found at least 13 cases in which she has filed claims in her name or her children's.
During the investigation, Wendy's said no employees at the San Jose restaurant had missing fingers, and no suppliers of Wendy's ingredients had reported any finger injuries. Authorities reported that there was no evidence the finger had been cooked.