You can trust old things. That's the logic of the ancient documents rule, which allows lawyers to introduce hearsay evidence so long as the document is old enough and appears authentic. How old is old enough? Just 20 years.
Ironically, that thinking is probably out of date, given the amount of digital data that can be hoarded away for long periods. If the logic behind the rule was questionable when it was established, some argue that it's even weaker now. The federal judiciary might agree. It decided earlier this month to consider ending the ancient documents rule altogether.