Require occupants 18+ years or older to fill out application?

[Emory Clayton]

I'm trying to understand the reasons....pros/cons.... to requiring occupants 19+ years or older to fill out application? In my state you have to be 19+ years of age or older to enter into a legally binding contract. I get having to require the tenant who reaches out to fill out and pay the application fee. My question is around requiring other occupants of the house who are not paying the rent to fill out an application. Is this because it allows me to further vet the occupants as a whole? Say for example the paying tenant checks out, but the spouse is a convicted murderer. Or maybe the husband and wife check out, but they have a 20 yr old son who lives with them who has a crime sheet a mile long?