Here is a solid example you can adapt for a joint venture (there are differences, beyond just nomenclature, for a partnership and a joint venture): https://templatelab.com/joint-venture-agreement/Again, I would caution use of this document without a professional to review it.

Sounds like you have a pretty poor security system.Even with a good security system, having a tenant provide ID is the first step in a professional screening process. 

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

It was listed by a realtor that I previously purchased a small portfolio from and therefore had a good professional relationship.

If you do not wish to pay the increased rent you may decide to seek other housing.

These are professionals with additional training and a stricter code of ethics.

Seek qualified legal guidance

Readers should seek professional advice.

Readers should seek professional advice.

So we restricted local landlords who rent to families, and soon the town will experience the very real repercussion of no one wanting to rent to families and professionals.