"How would you defend lending money to someone who was convicted of a serious crime and you knew this, through the negative new info?"
I have a local judge under indictment for drunk driving. He's still sitting on the bench pending the case going to trial. It's a huge to-do locally, but we'd still make loans to him. It would depend on the crime I suppose. We also have convicted sex offenders as customers, but they conduct their accounts in an appropriate manner and they have a legal source of income. Again, if the sentence has been served, and there is no indication of current criminal activity - I don't see what the risk is going forward -- but I guess that's a risk your bank has determined not to have.
On the other hand, I have customers that have defrauded or stolen money or neglected to make good on private loan arrangements with my board members that we won't make loans to, and thankfully, they have enough reported bad credit that that's our given reason (bad credit) -- and these deadbeats don't have any criminal history and we won't lend to them.