Tenant wants to have their own security system in apt building???

[Eric S.]

I have small apt building 10 units, one main front entrance and three back doors for each floor, there are 3 floors. I have a tenant or more so their parents that would like to have their own alarm system. Any thoughts on this. This unit does not have its own private entrance. It is actually right off the main front door.  My hesitations are if there were problem authorities would still need to get in the front door. Would need to know the code for maintenance.  If it goes off an error how can one shut it off. If she could not be contacted. Thanks and let me know your thoughts!