Quite right. Another matter is, to put it a bit harshly, the "quality" of the murder victims. Knock out deaths of gang members and drug deals gone bad and even the New Orleans numbers will be cut in half. It's a very small number of people in New Orleans who personally know somebody who was killed on their way out of a grocery store.
Knock out sectarian tit for tat in Iraq and you cut the numbers by a third or more.
When I read something, I compare it to what I know. In philosophy, the question is: Is an argument internally consistent?
New Orleans Police officers killed in the line of duty, 2005-2007: 0.
http://secure.cityofno.com/portal.aspx?portal=50&tabid=23
U.S. Casualties in Iraq, 2006: 785 KIA, other deaths 77, 6416 WIA.
http://www.globalsecurity.org/military/ops/iraq_casualties.htm
Iraqi security forces, KIA, 2006: 1543
http://www.strategypage.com/qnd/iraq/articles/20070103.aspx
If New Orleans was more dangerous than Iraq, one would expect that at least one police officer would have been killed in the line of duty since 2004. Not so, according to the NOPD web site.