Acquiring accurate rent roll?

[Jason Deutsch]

When looking to purchase a multiunit property. How does one acquire the correct rent roll to see what the exact income and vacancy is of the property? I understand that pro forma data can be inflated to make the property look like it is receiving more income at 100% occupancy. How do I know that the seller won't make up numbers in their rent roll to make it seem that their property receives higher rents & is occupied at full? Thanks!