There's no good day to throw lit firecrackers on the White House lawn. But today, the day of a tragic mass murder at the Washington Navy Yard, is definitely one of the worst. And yet, that's exactly what one man did on Monday evening, prompting a security alert at the White House and leading to the man's immediate arrest. He's unidentified. At the time of his arrest, the man wasn't wearing any shoes. Here's the AP with more: 

An Associated Press photographer heard what sounded like two gunshots outside the White House. Three uniformed Secret Service officers arrested a middle-aged man. The man was white, with dark hair, a blue shirt and white shorts. His white shoes lay on the ground near where the officer tackled him.

With media already on the scene, and on high alert, the incident and its response immediately captured attention: 

Based on eyewitness accounts, those noises were initially reported as shots fired. Thankfully that was not the case, and the incident appears to have little to do with the shootings themselves.