Complex sentence: A core principle of social disorganization theory is that place matters--i.e., one's residential location--as much or more than one's individual characteristics (age, gender, race) in shaping the likelihood that a person will become involved in illegal activities.
Split into simpler sentences: A core principle of social disorganization theory is that place matters. In other words, a person's residential location is a substantial factor shaping the likelihood that that person will become involved in illegal activities.