GRAND RAPIDS (WZZM) -- Murders committed in New York City have hit historic low this year, but the number of homicides is up in Chicago, Detroit -- and even Grand Rapids.

So far, Grand Rapids Police have investigated 17 murders in 2012. That's tied with last year -- the same year Roderick Dantzler went on a rampage, killing seven people. Officers are not sure what's causing the spike.

Grand Rapids' murder rate is a small fraction of Chicago's, where 500 people have been murdered this year, the highest rate since 2008.

Our partner, the Detroit Free Press, is reporting that Detroit homicides have reached 375 this year, the highest number in nearly two decades.