Tuesday, May 22, 2007

Crime Numbers

In March 2007, the NOPD released crime statistics for 2006 and lauded them for showing a reduction in crime compared to the year before:
The uniform crime report statistics show a 22 percent reduction in violent crime when compared to 2005 statistics, according to NOPD spokesman Sgt. Joe Narcisse.

Nonviolent crime dropped about 25 percent.

"In most categories you see a reduction in crime," Narcisse said.

Asked whether the statistics offer a fair assessment considering the post-storm chaos and radical reduction in population, Narcisse said the numbers speak for themselves.

"It is what it is," he said. "We may be able to (attribute) some of the reduction to Katrina."
It is what it is.

This week, the NOPD released their official crime stats for the first quarter of 2007. Compared with the same time period last year, there is no overall reduction to be lauded. In fact, violent crime is up 107 percent – more than double.

Hey NOPD, is it still what it is?
The NOPD did not return repeated requests for comment on the statistics Monday.
Wait, don’t tell me. Some of the increase in violent crime may be attributed to an increase in population, right?
Scharf, a frequent critic of the NOPD, called the city's murder rate alarming because it is a marked increase over the previous year without a corresponding increase in population.

A study recently released by GCR & Associates Inc. placed the city's population at 255,137 for March 2007. For January 2006, the start of the same quarter last year, the U.S. Census Bureau estimated that 158,353 were living in New Orleans. That's a population increase of 62 percent.

"You are 182 percent higher (in murders) than last year with a population that hasn't grown at that rate," Scharf said.
What the NOPD said last year [scroll down] around this time:
Although crime in New Orleans has risen as the population grows, the city is still much safer than it was before Hurricane Katrina, police Superintendent Warren Riley announced Friday as he revealed the city's first-quarter crime statistics.

The number of violent crimes reported to police -- murders, rapes, robberies, shootings, stabbings and other serious assaults -- was down by 64 percent in the first three months of this year [2006], compared with the same period last year [2005], Riley said.

The number of murders and armed robberies was down, each by about 74 percent, and nonviolent crime was down about 52 percent, Riley said.

Anticipating the argument that the decrease was insignificant because population is dramatically down in the city, Riley produced figures that he said show that even adjusting for the lower population, violent crime is still down about 26 percent and nonviolent crime about 1 percent, compared with the first quarter of last year. The figures are based on crimes per every 100,000 residents.
Maybe the first three months of this year was one of those “upticks” Mayor Nagin told us about.

Here’s the scary part. Let’s compare the first quarter of 2007 to the first quarter of 2005, the last Jan-Feb-Mar period when the city was at full pre-Katrina population.
First Quarter 2007

Murder - 48
Rape - 14
Armed Robbery - 190
Simple Robbery - 54
Assault - 447

Total = 753

First Quarter 2005

Murder - 65
Rape - 44
Armed Robbery - 284
Simple Robbery - 85
Assault - 530

Total = 1008
In the first quarter of 2007, total violent crime was down 25 percent from the first quarter of 2005. The only thing is, there were *almost twice as many people* in New Orleans in 2005. With around 56 percent (255,000) of the pre-Katrina population (455,000), we had 75 percent of the *total* pre-Katrina violent crime.

Using the “per 100,000 residents” method that Riley used in May 2006 to claim a 26 percent reduction in violent crime in the first quarter of 2006 as compared with the first quarter of 2005, the numbers say that violent crime is up 33 percent in the first quarter of 2007 (295 violent crimes per 100,000 residents) as compared to the first quarter of 2005 (221 violent crimes per 100,000 residents).

Assuming a first quarter 2006 population of 200,000 residents in New Orleans, violent crime is up 62 percent per 100,000 residents in the first quarter of 2007 (295 violent crimes per 100,000 residents) as compared to the first quarter of 2006 (182 violent crimes per 100,000 residents).

These comparisons aren’t really good for anything except showing that violent crime is not going down in 2007 when compared to the same time period after the storm *or* before the storm - on a per resident basis. But look at how close we are to the pre-Katrina total numbers of violent crime with around half the population. No numbers or formulas can make that look good.

1 comment:

Schroeder said...

Percentages are almost always deceptive compared to numeric changes.

That T-P reporter Brendan McCarthy is looking for any angle to create a sensation. When you actually look at the categories which caused the increases, it's thefts and assaults. A more experienced reporter might have paid closer attention to what kinds of assaults those were -- shootings, muggings?

Meanwhile, the decrease in murders, robberies, and rapes is nothing to be proud of when you count the number of incidents which did occur.