A crime is an act against the laws, so basically crimes are defined as crimes based on the laws and society.
Now for the reason people do these acts, since we just determined the only link (being a crime) as a subjective definition, it's only logic there are different reasons for each case and situation. The life situation of the criminal usually is an important factor.
I also don't think the bible has any say in this, as 1) it's moral values stem from society and not the inverse, and so the only that should follow it's specific commandments should be those who possess the appropriate set of belief, and 2) going against the commandments of the bible is technically not a crime, but a sin.