First investment property, Duplex red flags

[Jibril Ali]

Hello. I'm currently under contract for my first property, a duplex in GA. Both units have "long term" tenants in place. During the due diligence, it has been revealed that the seller does not have any security deposits to transfer, and only one unit has a lease. I also found that the property sold for 60% less than current asking only 6 weeks ago, there have been no improvements or changes to the property or major market shifts in that time. 

These things have made me quite nervous to continue with the purchase, I would appreciate any guidance as I am a newbie here. Thanks in advance!