General Practice for pest control in apartments

[James Conaway]

I have a 4plex in Phoenix, AZ that a tenant is complaining of cockroaches. What is the general best practice/policy for dealing with pest control like cockroaches in a shared building like a 4 plex?

Does the Landlord pay for professional pest control, does the tenant pay for it, is it split?

I appears to me that the landlord could get screwed by tenants (if he has to pay) to don't take care of their units and then all other units suffer and you will never really know which unit is the source...