Call location -- 2

I'm an information technology study pursing a bachelor's degree and am looking for my final project it's one that helps the police department to locate a crime based on a phone call for instance if some one calls to report theft they will be able to know the location based on the phone call and the program should have a kind of emergency word reserve which if said it bring an alert and it should be able to identify they call like true caller does....it should be well documented and a proper approach should be used preferably waterfall model