The letter is quite long but a great, well thought out, articulate read.
There's also a link on that page to a synopsis of the 8 major points made.
I want to comment on this passage:
I first saw this effect in the movie "In Days of Wine and Roses" when I was in high school. Jack Lemon's character sprayed Lee Remick's apartment for roaches and almost immediately EVERY OTHER tenant in the building screamed at him because they were being invaded.■ "During the CPL class last Saturday at Christ the King, a police officer from a suburb of Detroit who was conducting part of the class pointed out that because more Detroiters are protecting themselves, more of the criminals are now targeting the suburbs, because most of the suburbs consider themselves distant or immune from the threat. But in point of fact, as the officer pointed out, the threat is actually growing there. It is not just in the big cities either."
The second time was when I was living in an apartment in Charleston, SC in about '70 and our neighbor had Orkin spray her apartment and suddenly we were up to our knees in roaches. BTW - palmetto roaches give my heebies the jeebies.
Fast forward to 2004 when Ohio got concealed carry. Almost immediately Toledo saw a decrease in crime and the counties across the border in Michigan experienced an INCREASE in crime.
This effect was documented by John Lott in his study described in "More Guns, Less Crime."