Can you ask for financial obligations on application?

[Lauren Hulsman]

My husband and I are renting our townhouse for the first time and are really struggling picking the right tenant - we've had a lot of interest. We have it narrowed down to 3-4 people, who all seem like great fits. One application did not list out their financial obligations, which we're using to determine their debt to income ratio. Can I press them to list that information? 

Also - 3 out of the 4 are non-married couples...do you guys find it higher risk of one person leaving in those situations during the lease, especially if the couple has not lived together before?