What is circumstantial evidence?

Answer 1

Statements or information obtained indirectly or not based on firsthand experience by a person. Circumstantial evidence can include, in part, inferences about an event that was not seen. For example, if you walk outside and the ground is wet, and you didn't actually see it raining, you could infer that it had rained while you were inside.
If someone has a thing that they do not own and no explanation of how they now have that thing then either they got it from someone else or the fact that they have it is circumstantial evidence that they stole it