When you are making decisions about which tenant to accept into your property, you will of course want to phone landlords for references. Be sure to get references from previous landlords; don’t stop with only the current landlord.
If this tenant has been a problem, the current landlord may give them a glowing recommendation just to move them out of their building and into yours! Be sure to check previous landlords whenever possible. You may get a very different story about what kind of tenant they are.