That is a pretty massive subject. Luckily for you it has been done thousands of times before. Stand on the shoulders of giants and get some proper research into it.
Get a hold of the social trends and look at the crime rates over the years.
I did not do sociology but I did social policy. Some of the questions we had to ask was
"do you think crime rates have increased in the past 10 years?"
"do you think crime rates have increased in poorer areas in the past 10 years?"
Quite often public opinion is different from statistics because public opinion is mostly based on media.
Do some research into poorer areas and the types of crime committed. Also take into account that statistics can only include crime that is reported. I think you will see that the type of crime varies according to how affluent the area is.
Like I said there is a lot of information already out there, providing you credit it as part of your research you can get a good idea about the sort of questions to ask people and whether those questions are of any value to your hypothesis.