Predictive analytics for crime - its been done before. Look for previous research tackling this problem to see what existing strategies are and build from there
How detailed will your predictions be? Zip code level? Census tract level? Block level?
Contrasting case studies - a good entry point
How much data cleaning will need to occur? Do the two cities use the same reporting system and database structure?
Have you taken classes with Luc Anselin? He does tons of spatial data work, might be a good reference for this paper
With two separate cities, be sure to make similar comparisons. That is, you are measuring or predicting the same underlying construct/phenomena in both cities
Are any of these algorithms specifically tuned for temporal or spatial data structures?