The Detroit News ran an article the other day stating that Detroit’s murder rate in 2014 is the lowest in decades. I got interested when I saw the phrase, “Taking population into consideration…” I’m not really interested in quibbling with homicide statistics, I just always find instances when the population comes up interesting, and like to look into what stats people are using.

From the article:

“Taking population into consideration, the murder rate per 100,000 residents is on pace to drop for the third straight year, from 55 in 2012, to 47.5 last year, to 42.6 so far in 2014.”

So, I was curious what population estimate the News (or DPD, not sure where the #’s came from) used to arrive at the 42.6 rate in 2014.

So far there have been 298 murders in Detroit in 2014. The 2013 population estimate for the city from the U.S. Census Bureau is 688,701 (most recent data available). Carrying over that population estimate into 2014 would suggest a homicide rate of 43.3 this year, a bit higher than what the News / DPD reports.

Using the 2012 population estimate of 698,582 for 2014, however, returns the 42.6 rate from the article.

But the 2014 population of Detroit is almost certainly lower than 2012 or 2013 – figure conservatively another loss of 10,000 people. That’d put the population closer to 678,000 and the homicide rate at 44 per 100,000 residents.

Again, the point isn’t to call anyone out for a +/- 1.4 homicides / year differential, I’m just interested in where the population statistics for these kinds of numbers come from. I look forward to seeing the 2014 population estimates from the U.S. Census Bureau.

Here’s a breakdown of the homicide rate, year by year for 2010 & 2012 - 2014. These numbers are a bit different from the News’ but it’s not because of population, but rather because of whether you choose to include “justifiable” homicides or not. I think the News did not, but I left them in.

2010: 308 Homicides / 713,862 Population = 43.1 Homicides / 100,000 People

2012: 411 / 698,582 = 58.8 Homicides / 100,000 People

2013: 333 / 688,701 = 48.3 Homicides / 100,000 People

2014: 298 / 678,000 (guess) = 44.0 Homicides / 100,000 People