Questionable tenant application

[Victoria S.]

We just bought a duplex. One side came with a long term tenant. The other side is vacant. We just had a 60 y/o retired applicant, her son (in his 30s) and grandson apply. The income is 3x the rent. however the retiree applied for bankruptcy in June 2018 for medical bills. They could move in ASAP.  We would do a background check and credit score on both the retiree and son. She says her credit score is >600. Would you consider this tenant? If so, would you ask for extra security ect?