The man said the attack occurred in Foothills Park around 4 p.m. Saturday, but California Department of Fish and Game investigators Monday determined the attack may not have happened based on lack of evidence.
Inspectors looked for tracks or hairs but could not find anything to validate the attack, according to California Department of Fish and Game spokesman Steve Martarano.
But police interviewed the man again Thursday, who reportedly maintained he was attacked by a large animal, possibly a shaggy dog or a mountain lion, Palo Alto police agent Dan Ryan said.
Despite the fact that the claim prompted police to shut down Foothills Park on Sunday, as well as Enid Pearson Arastradero Reserve where a mountain lion was reportedly sighted Saturday afternoon as well, the man will not face charges.
"We don't have enough to prove anything as far as a crime by him, so we're just going to drop the case," Ryan said.
Instead, the alleged attack will go on record at the Police Department as a "suspicious circumstance case," Ryan said.