I agree with most folks that this approach is probably going to be impractical.

However, there is one thing that they could do. They could give some sort of rating to neighborhoods based on police report statistics. For example, you could get a number from the GPS that reflects the data on number of homicides per year, or number of auto burglaries per year. It doesn't have to be the actual crime number - just some sort of rating that is proportional to the crime rate in that area.

Pete2