KANSAS CITY, Mo. (AP) — Federal and state officials are pooling millions of dollars to add more police officers to combat Kansas City's gun violence, but research has shown that changing the way police interact with people is likely to have a greater impact on crime reduction.

Kansas City, Missouri, is on its way to report about 150 homicides and officials are projecting another 500 nonfatal shootings by year's end.

Last week, the Justice Department announced that it will intensify federal law enforcement resources in seven cities, including Kansas City along state lines, in an effort to crack...