My last two posts on this blog have sought to explain how I built a foundation from which analysis of gun violence is possible. The first post discussed some of the analytic problems created by the country’s traditional focus on murder, and the second post showed how data transparency in New Orleans can be used to advance an analytic agenda.

This foundation can now be used to look at both the “what” and the “why” behind changes in gun violence in New Orleans. It has been well advertised that murder in New Orleans dropped approximately 20 percent in 2013, but not much ink has been spilled on analyzing why murder went down. Most of the expert “analysis” of 2013’s decline in murder either claims overall gun violence did not decline or gives credit to new medical techniques learned in Iraq and Afghanistan since 2001 but apparently only first implemented in 2013.

Adding to the foundation of the first two posts by truly analyzing why murder fell in 2013, therefore, is the goal of this post.

Conducting this analysis is important because it highlights how it takes just a little bit of work on the back end to develop a system from which the city’s transparency can be used to accurately assess the city’s policies. Rather than relying on a sense of analytic helplessness, reviewing 2013’s murder reduction proves how analysis of publicly available data can help answer important questions about the city’s anti-gun violence efforts.

After this post I’ll take a look at what happened in 2014, and then I will discuss in a subsequent post what may be causing murder to rise in 2015. This will allow ongoing analysis of gun violence trends in New Orleans in near real time.

But first let’s take a look at what happened in 2013.

NOLA Gun Violence in 2013

The bottom line of analyzing New Orleans gun violence in 2013 is that there is a strong relationship between the specific city tactics implemented from late 2012 through the end of 2013 and the nearly 20 percent reduction in shootings in 2013.

The city’s success against gun violence in 2013 is typically noted by pointing out how the number of murders fell from 193 in 2012 to 156 in 2013. As I have previously argued, murder is a bad statistic for measuring gun violence and evaluating the effectiveness of the city’s programs. Eschewing murder and applying the data collection and analysis method laid out in the last post shows a pretty clear reduction in New Orleans gun violence in 2013 no matter how you slice it.

The below table shows changes in gun violence incidents (rather than victims) from 2011 through 2013 broken down by non-fatal incidents, fatal incidents and total shooting incidents. As noted in the previous post, these incident totals are not perfect but they do provide a good representation of the overall trends.

Estimated shooting incidents in New Orleans, 2011-2013. Source: NOPD.

This table shows how, in addition to the roughly 20 percent reduction in murders, New Orleans experienced nearly a 16 percent drop in non-fatal shooting incidents, a 22.5 percent drop in fatal shooting incidents, and an 18 percent drop in overall gun violence incidents. This is good data, but those numbers by themselves don’t provide any context into why gun violence decreased and whether it was the result of the city’s strategies or some alternative explanation.

The above table shows what happened in 2013, but to understand why gun violence fell in 2013 it is necessary to take a closer look into the city’s gun violence reduction program: NOLA for Life.

NOLA for Life is a “comprehensive murder reduction program” implemented by the city in May 2012, with various aspects phased in over the ensuing year. NOLA for Life has over 30 initiatives listed on its website, but this analysis focuses on the impact of the two primary anti-gang tactics employed by the city: the “call-in” and the gang indictment. These two tactics make up the backbone of the city’s Group Violence Reduction Strategy (GVRS), which has been credited with reducing murder in the city.

The call-in is a community forum conceptualized by David Kennedy of the John Jay College of Criminal Justice. These events are described as:

A meeting during which a partnership of law enforcement representatives, influential community members, and social service providers speak directly to members of street groups (usually those on probation or parole). The [cities] use the meeting to deliver the strategy’s no-violence message to group members and, through them, back to their associates. During the call-in, the [city] partnership clearly communicates (1) a credible, moral message against violence; (2) a credible law enforcement message about the group consequences of further violence; and (3) a genuine offer of help for those who want it.

New Orleans held five of these call-ins under the NOLA for Life umbrella between late 2012 and the end of 2013. A review of open sources reveals call-ins took place in October 2012, February 2013, May 2013 and December 2013. Another call-in likely took place sometime around August or September 2013, assuming the city followed the same rough schedule for its fourth call-in (no news articles on this call-in appear to have been written). These events were attended by approximately 159 gang members through the end of 2013, according to the city.

The other major tactic employed by the city is the gang indictment. The city indicted over 70 alleged gang members from seven gangs between mid-2012 and the end of 2013, according to a review of open sources. These federal and state efforts tie multiple (as many as 20) gang members together into one indictment, which allows for stiffer penalties and raises the likelihood of cooperation from the defendants. Public comments by city law enforcement officials paint this tactic as particularly effective in cracking down on gang activity.

The seven gangs targeted by the city between late 2012 and the end of 2013 were:

  • 6 alleged members of a Hollygrove gang were indicted in November 2012.
  • 5 alleged members of the 7th Ward MMG gang were indicted in April 2013.
  • 15 alleged members of the 110ers Gang were indicted in May 2013.
  • 7 alleged members of a gang tied to Burnell Allen were indicted in June 2013.
  • 20 alleged members of the 3-N-G Gang were indicted in June 2013.
  • 8 alleged members of the Taliban gang were indicted in August 2013.
  • 12 alleged members of the Ride or Die gang were indicted in September 2013.

With the city’s tactics laid out, analysis can turn to evaluating what role the anti-gang efforts played in the 2013 overall reduction in gun violence. This analysis suggests there is a strong relationship between city anti-gang activity and fewer shootings.

The below chart shows changes in the pace of shooting incidents in New Orleans from mid-2011 through the end of 2014 in order to highlight this relationship more clearly. The pace in this chart covers 120 days, so each point along the pace line represents the number of shooting incidents the city would experience over a full year at the pace of shootings experienced over the previous 120 days.

This chart starts in mid-2011 because the pace during the first few months of the graph is more chaotic before the data settles down. Appended to the pace line are dots representing the timing of the city’s anti-gang initiatives. The blue circles represent the timing of call-ins and the green circles represent gang indictments.

Change of Pace (120 Days), mid-2011 through 2013. Source: NOPD.

As can be seen, gun violence vacillated fairly steadily between mid-2011 and right around April 2013. Then things changed around April 2013. The timing of the decline matches up closely with the implementation of both the call-ins and the indictments picking up steam. By the end of 2013, the city was experiencing shootings at a 120 Day Pace of 290 shootings, down substantially from the shooting pace of roughly 450 shootings the city had experienced with relative consistency between 2011 and early 2013.

On the morning of May 1, 2013, New Orleans was on pace to finish 2013 with 450 shooting incidents. Likely because of the city’s efforts, it ended the year with around 360.

The relationship between the anti-gang programs and the reduction in shootings is further illustrated through a quick regression analysis chronologically comparing the change in shooting pace to the number of people indicted and to the number of people attending call-ins. This regression analysis shows a strong relationship between the timing of the shooting reduction and both the number of people indicted (r-squared = 0.6) and the number of people called in (r-squared = 0.5).

The result of this analysis is that, while it is difficult to say which tactic was most effective, it is likely that the city’s anti-gang efforts played a large role in 2013’s gun violence reduction.

This is a critical insight that deserves attention not just for the conclusion itself, but also because of how it was reached through analyzing publicly available data.

Next Up:

The true value of this process is to deliver analytic insights into current gun violence trends in near real time, so in my next post, I will look at gun violence in New Orleans from the beginning of 2014 to the present. My goal will be to explain why murder fell while gun violence rose in 2014 and how randomness may explain why murder is rising in 2015.