As towns, such as Eoforwic (York) and Lundenwic (London), grew in importance, there was more opportunity for both crime against the person and crime against property.
In towns, people did not know each other well, so it was easier to get away with crimes.
The concentration of goods and money meant there was more of value to steal.
The development of a social structure of king,nobles,freemen and serfs meant that actions that threatened this system were considered crimes against authority: for example, a serf starting a fight with a noble.
The worse crime against authority was treason: betraying the king.
Actions that were against religious beliefs (for example, having sex outside marriage) were considered moral crimes.