When Your Security Deposit isn’t Enough??

[Akeim Fin]

TLDR: When your tenant bails  and the security is not enough to cover expenses what do you do? How do you find them? If the cost for repairs is low (~$500) is it worth it? What kind of information is needed to send to Collections ? 

I recently purchased a turnkey 3 family that I am house hacking. With the purchased I inherited some tenants. One of the tenants got the family hook up as they are related to the seller/flipper. (About $250 under market value). No one likes new management and their no exception. Their lease is coming to an end and I notified them that I intend to raise the rent $150. Of course they intend to leave but they ask for their security before they move (NOOO) so they can move into their new place. And it appears they are going to just break the lease as they still have a mouth left and move into their new place.

I can see them not paying the last month and moving out. This leaves me with the security to cover the missed rent but nothing for repairs. I asked for their new address so I can send their security deposit and have gotten nothing. So what do you do if this plays out how I predict? How can I better protect myself from this in the future? First, Last and security is allot to ask for.