An FBI expert's comparison of Aurora shooting suspect James Holmes' booby-trapped apartment to a "house bomb" refers to a technique popularized by Iraqi insurgents in the Diyala Province but apparently never before used in the United States. Retired FBI agent James Lopez made the comparison on CNN's broadcast, Reuters reports: "This would be one of the first times I think we have ever seen what we can describe as a house bomb in the United States." He said of the technique, which involves rigging a building with explosives and then luring your enemy in, "we've seen them in places like Iraq and Afghanistan." Specifically, the roots of this technique can be traced to the Diyala Province, in Iraq. 

Prior to the reports of Holmes' booby-trapped apartment, the place you would have been most likely to see the phrase "house-bomb" would have been in reports such as the The Washington Post's, from 2007, or the Wall Street Journal's, from 2008, about the technique's prevalence  among Iraqi insurgents fighting U.S. troops. The Post's Megan Greenwell reported that "the tactic appears to have spread south from Diyala province, northeast of the capital," and The Journal's Yochi Dreazon wrote that the tactic was the "calling card" of insurgents in the Diyala Province. "This is the first one that I can actually recall ever reading or seeing about in the United States where it was actually set to destroy the home," Lopez said. CNN had reported earlier that Holmes' 800-square-foot apartment was rigged with 30 homemade bombs, gasoline, and trip wires. One unnamed law enforcement official told CNN's Poppy Harlow and Ed Payne, "That flame would have consumed the entire third floor (of the apartment complex)."