On Monday afternoon, federal prosecutors charged Dzhokhar Tsarnaev with "using a weapon of mass destruction against persons and property at the Boston Marathon.”

Charging the Boston bombing suspect in federal court — rather than in a state court — allows prosecutors to pursue the death penalty, which isn’t allowed in Massachusetts. Going into the complaint, many questioned how the Obama administration would be able to claim federal authority.

Reading the complaint, signed by FBI Special Agent Daniel Genck, one finds multiple references to commerce. It reads that the Boston Marathon has a “substantial impact on interstate and foreign commerce. For example, based on publicly available information, I believe that the runners and their families — including those who travel to the Boston area from other states and countries  — typically spend tens of millions of dollars each year at local area hotels, restaurants and shops, in the days before, during, and after the Marathon. In  addition, a number of the restaurants and stores in the area near the finish line have special events for spectators.” The complaint goes on to note, “The explosions had a substantial impact on interstate and foreign Commerce. Among other things, they forced a premature end to the Marathon and the evacuation and temporary Closure of numerous businesses along Boylston Street for several days.”

The commerce argument is central to the DOJ’s claim that the bombing is an issue for federal court. Under the U.S. Code, the Use of Weapons of Mass Destruction charge has several possible criteria, one of which is that “the offense, or the results of the offense, affect interstate or foreign commerce.”