culprit; may have caused the act but may not have (yet) been found or been found guilty of the crime. Can be a person, a company or an object
Perpetrator; as culprit, most likely a human but could also be a company or an animal. Not an object, so a storm could not be a perpetrator but it could be a culprit
Criminal; someone who has been judged by a court of law to have commited a crime. Note that in some countries in history an animal could also be convicted of a crime. A company can also be a criminal. No objects can be a criminal.