For my discussion of semiautomatics and gun control, I relied on Mark A. R. Kleiman’s excellent When Brute Force Fails: How to Have Less Crime and Less Punishment (Princeton, N.J.: Princeton University Press, 2009), especially pp. 8–15 and 136–148. For the gun-control perspective, I read Tom Diaz’s Making a Killing: The Business of Guns in America, especially pp. 1–16 and 83–84; Dennis A. Henigan’s Lethal Logic: Exploding the Myths That Paralyze American Gun Policy, especially pp. 1–12 and 37–73; and Josh Sugarmann, Every Handgun Is Aimed at You: The Case for Banning Handguns, especially pp. ix–xvii and 1–11. Criminologists’ difficulty in explaining crime rates is discussed trenchantly in Shaila Dewan, “The Real Murder Mystery? It’s the Low Crime Rate,” New York Times, August 2, 2009. Background on the Virginia Tech killings can be found in Bill McKelway and Peter Bacque, “Killer Bought Handgun, Ammo Last Month: Roanoke Shop Owner Says Sales to Cho Didn’t Raise Any Suspicions,” Richmond Times-Dispatch, April 18, 2007; Jerry Markon and Sari Horowitz, “Va. Tech Killer’s Motives Pursued: Some Actions During Rampage Still a Mystery,” Washington Post, April 26, 2007; and Jerry Adler, “Story of a Gun: It’s Sleek, Light, and Frighteningly Lethal. How the 9mm Became the Weapon of Choice for Cops and Criminals, Civilians and Soldiers—and a Very Sick Young Man in Virginia,” Newsweek, April 30, 2007. For background on the Diallo shooting, I relied on Jodi Wilgoren, “Fatal Police Barrage Renews Debate Over Safety of Semiautomatics,” New York Times, February 7, 1999, and Jane Fritsch, “The Diallo Verdict: The Overview—4 Officers in Diallo Shooting Are Acquitted of All Charges,” New York Times, February 26, 2000. On the Sean Bell case, I read Michael Wilson, “50 Shots Fired, and the Experts Offer a Theory,” New York Times, November 27, 2006; Clyde Haberman, “Yes, There’s a Trial, but There Are Also Broader Statistics,” New York Times, February 29, 2008; and Michael Wilson, “Police Guns Make Jarring Evidence at Detectives’ Trial,” New York Times, March 6, 2008. Contagious shooting is addressed by Ray Rivera and Al Baker in “Bystander Injured in Harlem Episode Cites ‘Contagious Shooting’ in Plan to Sue,” New York Times, August 11, 2010. The Time piece on ATF crime gun traces is Elaine Shannon, “America’s Most Wanted Guns,” which ran on July 12, 2002.