What is the syndrome called when a person feels bad for the criminal instead of the victim?

Compassion is always important, but where a criminal is attracting sympathy while the victim is disregarded, I'd call that misplaced sympathy.

This may or may not be the answer , but there is a phenomenon called the "Stockholm Syndrome" where a person in captive type situations, like kidnap victims or battered wives, begin to identify with their captors and relate to them as friends instead of enemies. The terror the person feels at first is lessened by later acts of kindness so much so that the psychological relationship between them is changed. The initial sense of fear disappears and a sense of relief then compassion comes in.