Today, Boston Marathon Bomber suspect Dzhokhar Tsarnaev was charged with the bombings on April 15th. The official complaint stated the following charges:
3. This affidavit is submitted in support of an application for a complaint charging DZHOKHAR A. TSARNAEV of Cambridge, Massachusetts (“DZHOKYAR TSARNAEV“) with using a weapon of mass destruction against persons and property at the Boston Marathon on April 15, 2013, resulting in death. More specifically, I submit this affidavit in support of an applications for a complaint charging DZHOKHAR TSARNAEV with (1) unlawfully using and conspiring to use a weapon of mass destruction (namely, an improvised explosive device) against persons and property within the United States used in interstate and foreign commerce and in an activity that affects interstate and foreign commerce, which offense and its results affected instate and foreign commerce (including, but not limited to, the Boston Marathon, private businesses from Eastern Massachusetts, and the City of Boston itself), resulting in death, in violation of 18 U.S.C § 2332a; and (2) maliciously damaging and destroying, by means of an explosive, real and personal property used in interstate and foreign commerce and in an activity affecting interstate and foreign commerce, resulting in personal injury and death, in violation of 18 U.S.C. § 844(i).
Additionally, the affidavit presented a timeline of the Tsarnaev brothers’ movements in the minutes before the explosions:
B. Surveillance Evidence
9. I have reviewed videotape footage taken from a security camera located on Boylston Street near the corner of Boylston and Gloucester Streets. At approximately 2:38 p.m. (based on the video’s duration and timing of the explosions) – i.e., approximately 11 minutes before the first explosion – two young men can be seen turning left (eastward) onto Boylston from Gloucester Street. Both men are carrying large knapsacks. The first man, whom I refer to in this affidavit as Bomber One, is a young male, wearing a dark-colored baseball cap, sunglasses, a white shirt, dark coat, and tan pants. The second man, whom I refer to in this affidavit as Bomber Two, is a young male, wearing a white baseball cap backwards, a gray hooded sweatshirt, a lightweaight black jacket, and dark pants. As set forth below, there is probable cause to believe that Bomber One is Tamerlan Tsarnaev and Bomber Two is his brother, DZHOKHAR TSARNAEV
10. After turning onto Boylston Street, Bomber One and Bomber Two can be seen walking eastward along the north side of the sidewalk towards the Marathon finish line. Bomber One is in front and Bomber Two is a few feet behind him. Additional security camera video taken from a location farther east on Boylston Street, as well as contemporanous photographs taken from across the street, show the men continuing to walk together eastward slong Boylston Street towards Fairfield Street.
11. I have also reviewed video footage taken from a security camera affixed above the doorway of the Forum Restaurant located at 755 Boylston Street, which was the site of teh second explosion. This camera is located approximately midway between Fairfield and Exeter Streets and points out in the direction of Boylston and is turned slightly towards Fairfield. At approximately 2:41 p.m. (based on the video’s duration and the timing of the explosions), Bomber One and Bomber Two can be seen standing together approximately one half-block from the restaurant.
12. At approximately 2:42 p.m. (i.e., approximately seven minutes before the first explosion), Bomber One can be seen detaching himself from the crowd and walking east on Boylston Street towards the Marathon finish line. Approximately 15 seconds later, he can been seen passing directly in front of the Forum Restaurant and continuing in the direction of the location where the first explosion occurred. His knapsack is still on his back.
13. At approximately 2:45 p.m., Bomber Two can be seen detaching himself from the crowd and walking east on Boylston Street toward the Marathon finishing line. He appears to have the thumb of his right hand hooked under the strap of his knapsack and a cell phone in his left hand. Approximately 15 seconds later, he can be seen stopping directly in front of the Forum Restaurant and standing near the metal barrier among numerous spectators, with his back to the camera, facing the runners. He then can be seen apparently slipping his knapsack onto the ground. A photograph taken from the opposite side of the street shows the knapsack on the ground at Bomber Two’s feet.
14. The Forum Restaurant video shows that Bomber Two remained in the same spot for approximately four minutes, occasionally looking at his cell phone and once appearing to take a picture with it. At some point he appears to look at his phone, which is held at approximately waist level, and may be manipulating the phone. Approximately 30 seconds before the first explosion, he lifts his phone to his ear as if he is speaking on his cell phone, and keeps it htere for approximately 18 seconds. A few seconds after the finishes the call, the large crowd of people around him can be seen reacting to the first explosion. Virutally every head turns to the eat (towards the finish line) and stares in that direction in apparent bewilderment and alarm. Bomber Two, virtually alone among the individuals in front of the restaurant, appears calm. He glaces to the eat and then calmly but rapidly begins moving to the west, away from the direction of the finish line. He walks way without his knapsack, having left it on the ground where he had been standing. Approximately ten seconds later, an explosion occurs in the location where Bomber Two had placed his knapsack.
15. I have observed video and photographic footage of the location where the second explosion occurred from a number of different viewpoints and anges, including from directly across the street. I can discern nothing in that location in the period before the explosion that might have caused that explosion, other than Bomber Two’s knapsack.
The full affidavit is available here, and includes more information about the photographic evidence used by the FBI to piece together the suspects actions that day.