Tenant vs. Previous Owner: Security Deposit & Last Months Rent

[Matthew B.]

I purchased a property from a motivated seller. The property is tenant occupied. The seller stated he was not holding a security deposit or last months rent for the tenant. 

After closing, the tenant is refusing to pay rent - saying the previous owner has his security deposit and last months rent. He wants to use both for October and November rent, and move out at the end of November. The previous owner still denies holding any money for the tenant.

I'm stuck in the middle. Planning on filing for eviction. I'm assuming the tenant will have to prove he paid the security deposit and last months rent to the previous owner back in 2013?