Someone says they walked your dog and he got away. 2 months later and still no sign of dog. Flyers posted craigslist and fb postings. Checked dog shelters.
What could be considered evidence is something that depends on the circumstances. In your case, it seems that you would need something to prove that they had your dog, or control of your dog, after the time they say it ran away. Were they seen with the dog? Are they advertising a dog for sale? Is someone close to them housing the dog? You would need something to prove that they lied.
