That's a good question. Not being a CPI, but having worked in this area for over 7 years, I would hazard a guess and state that they run a cursory background check on the alleged abuser initially, while pulling all prior abuse reports. However, regardless, in this case, even if that person has a prior criminal history, the question centers on this particular instance of alleged abuse. Cases are categorized as founded/verified, some indicators, or unfounded. If unfounded, the Department really has no power to be involved solely because of someone's prior record (unless there is something in that record, such as child molestation, that would cause that child to be independently in danger in light of the same).