The WaPo wrings its hands about Florida's "Stand Your Ground" law; they recycle some brain-locked social science that has been circulating for a while (and was cited by the New York City Council in their resolution supporting Trayvon Martin):
According to the Tampa Bay Times [link], Florida experienced an average of 34 “justifiable homicides” before 2005; two years after the Stand Your Ground law was enacted, the number jumped to more than 100. Similarly disturbing spikes have been found in other states with similar laws. According to an analysis of FBI data done by the office of New York Mayor Michael R. Bloomberg (I) [link], who co-chairs the 650-strong Mayors Against Illegal Guns [link], states that passed Stand Your Ground laws experienced a 53.5 percent increase in “justifiable homicides” in the three years following enactment; states without such laws saw a 4.2 percent increase.
The obvious response - if the law expands the definition of justifiable homicide, then one might reasonably expect the number of cases newly classified as justifiable homicide to go up whether human behavior changes or not. (If we formerly defined a tall person as “over six feet” and change that to “over 5’ 8″, the number of ‘tall’ people goes up. Later I will explain how to boil water...)
The question (not addressed by the WaPo, but perhaps in the study) is whether there is an offsetting drop in cases previously classed as negligent homicide (or something else, such as voluntary manslaughter).
In other words, has behavior changed, leading to more total gun deaths, or has behavior remained unchanged while the classification scheme has changed? If gray-area, coulda gone either way killings are about the same, that would seem to make a difference in determining whether this new law has led to some sort of crisis.
A possibly fruitful avenue for an eager social scientist would be this: look at some plausible sampling of Florida homicides from 2004 (pre-revision) that were either treated as justifiable or negligent (for simplicity, I will assume those are the only two possibilities; voluntary manslaughter may be the term I am looking for to describe a self-defense killing). Then enlist some legal talent to guess how many of the negligent homicides would have been reclassified as justifiable under the new law. The result would be a baseline projection in the impact of the new law if behavior does not change. (Obviously, data collection may be an issue - a case that was open and shut negligence under the old law may have not left enough of a paper trail to guess its disposition under the new law.)
Or, one could look at actual cases: Politfact sorta-kinda did that and found that in Florida justifiable homicides roughly tripled. They leave unremarked that justifiable homicides by police officers (presumably not covered by the new law) also tripled. Weird. They don't make the obvious point about any drop in reclassified negligent homicides, or put this in perspective with total gun deaths or total murders in Florida. FWIW, I see 987 murders in 2010 versus 40 justifiable homicides by civilians; if I were threatened by a stampede of mice and elephants...
For a different look, let's get some help from the NY Times; writing in August 2006, Adam Liptak advises us that:
In the last year, 15 states have enacted laws that expand the right of self-defense, allowing crime victims to use deadly force in situations that might formerly have subjected them to prosecution for murder.
Well, here are the FBI Uniform Crime Reports for justifiable homicides by civilians, nationwide, 2000 to 2010. I am posting pages from the 2006 and 2010 reports, which collectively cover 2002 to 2010. Don't ask me why the numbers differ for 2006 between the reports; They are close, and I assume revisions.
Out national crisis - from 233 justifiable homicides in 2002 to a low of 196 in 2005, followed by an increase to 278 in 2010. And where handguns were employed? From 158 down to 123 in 2005 and back to 170. That is against total homicides of 12,996 in 2010, which is down from roughly 16,000 in 2002 (I am looking at the 2004 report with numbers for 2003; the earlier reports are in a different computer format). Let me add:
The UCR Program does not include the following situations in this offense classification: deaths caused by negligence, suicide, or accident; justifiable homicides; and attempts to murder or assaults to murder, which are scored as aggravated assaults.
Negligent homicides reports, anyone? Obviously, with automobiles and weapons separated.
NOT WHAT I HAD IN MIND, BUT INTERESTING:
Murder and Non-Negligent Manslaughter
According to the UCR Program, murder and non-negligent manslaughter are defined as the willful killing of one human being by another. The classification of this offense is based solely on police investigation as opposed to the determination of a court, medical examiner, coroner, jury, or other judicial body. Not included under this classification are deaths caused by accident, suicide, negligence, or justifiable homicides. 2
According to figures compiled by the UCR program, 61% of all murders committed in Florida, from 1996 through 2007, involved a firearm (see Figure 4). During this time period, there were 11,658 murders committed in Florida. As illustrated in Figure 4, the patterning of firearm-related murders is parallel to that of all murders. Figure 5 displays non-negligent manslaughter firearm trend. From 1996-2007, 1,505 non-negligent manslaughters were reported in Florida. Approximately nine percent of those reported involved a gun. Although the reported number of non-negligent manslaughters has annually increased since 2002, the number of incidents that were firearm-related has remained relatively stable; no more than 20 incidents have been reported during this time frame.
Reportedly the lead investigator in the Zimmerman case wanted a charge:
A Sanford Police incident report shows the case was categorized as “homicide/negligent manslaughter.”
That would be rare in Florida, if I understand the FDLE report.
Combining the FDLE report with the Politifact numbers, we are getting roughly 10-20 negligent homicides per year in Florida from 1996-2007, versus about 12 justifiable homicides annually before 2005 and 35 annually afterwards. I think I am still missing manslaughter cases, which would be how some self-defense cases should have been resolved.