Assertion: zodiac's clue | /r/CapableOf | provide the solution
Facets:
value: to the case
type: OTHER
Source sentences:
text: Marked USPS for the United States Postal Service, the keys had identification numbers of undetermined significance, leading to speculation that the Xerox might lead to a post office box containing the identity of the Zodiac, or some other clue that could provide the solution to the case.