Have your attorney contact the former owner and Talk to your attorney about drawing up a letter for you ( so you can make extracopies for distribution ) you want the letter to tell the tenants that failing to comply with your request to provide a copy of the lease they have sets the tone for their tenant landlord relation ship with you to start on a negative path and could possibly lead to them facing a court where a judge can make them produce a copy of the lease. 2nd The day you plan on going to talk to the tenants , have with you a copier printer and a second person like your spouse , plug it in, test it to make sure it works, this way you can do it on the spot for those who will with out a hassle go get their copy and go with you to the copier and get it done, any one who hesitates, hems haws or refuses plan for a second trip to give them time and if they wont comply second time you go there then send to them in certified mail a copy of the letter addressed to them. Hopefully by the time that happens you have enough copies of the leases that you might be able to spot fakes if someone used just any old blank form .