So this is explanation # 3 from First American and it still isn't specific.  They should be able to quote chapter & verse and provide you with a coherent and comprehensive explanation as to why they are now requiring criminal background checks rather than what looks more & more like a giant run-around.  It sounds as if they really have no idea why they want this - just that they do.

When I took an in-house examiner job I was asked to bring all kinds of documentation with me - including my original social security card - but the company had a clear & compelling explanation of what the information was going to be used for along with how/where it would be stored and who would have access to it.  That was reasonable - this is not.