The Evidence: Tsarnaevs' movements detailed in affidavit

amerlan Tsarnaev, third from left, who was dubbed Suspect No. 1 and second from left, Dzhokhar A. Tsarnaev, who was dubbed Suspect No. 2 in the Boston Marathon bombings by law enforcement. — AP Photo/Bob Leonard

Chilling new details and a clearer picture of the actions of the suspects in the moments before the Boston Marathon bombings have emerged from the criminal complaint against 19-year-old Dzhokhar Tsarnaev.

Here, the pair is seen 10 - 20 minutes before the attack, about a block-and-a-half from the blast site. Continue reading for a photo timeline and details from the affidavit laying out the federal case.

2:38 p.m. ET

Boston marathon bombing suspects video grab

2:38 p.m. ET: Approximately 11 minutes before the bombing, Bomber One, with the black cap, and Bomber Two, with the white cap, were seen turning left onto Boylston Street, the site of the finish line. The FBI has identified Bomber One as Tamerlan Tsarnaev and Bomber Two as his brother Dzhokhar.

Read the full criminal complaint here

2:38 p.m. ET

Boston Marathon bombing suspects are seen in this surveillance video released by the FBI on April 18, 2013.

Read the full criminal complaint here

2:38 p.m. ET

Bomber Two in the Boston Marathon bombing is seen carrying a backpack in this surveillance video released by the FBI on April 18, 2013.

Read the full criminal complaint here

2:42 p.m. ET

2:42 p.m. ET: A map shows where the bombing suspects spilt up, with Tamerlan Tsarnaev heading toward the finish line while Dzhokar blends in with the crowd. According to the affidavit, about 15 seconds later Bomber One can be seen walking past the Forum Restaurant and continuing with his backpack toward the finish line, in the direction of where the first explosion occurred.

Read the full criminal complaint here

2:45 p.m. ET

2:45 p.m. ET: Bomber Two breaks from the crowd and moves toward the finish line, stopping in front of the Forum Restaurant, pictured, and facing the race amid the crowd. A photo from across the street shows a backpack has moved to the ground in front of his feet.

Read the full criminal complaint here

2:50 p.m. ET

According to the affidavit, about 30 seconds before the first explosion, Bomber Two holds his cell phone to his ear. After the explosion he appears calm and slowly turns his head east toward the finish line, then begins moving west without the backpack. The second blast occurs in front of the restaurant, about 15 - 30 seconds after the first.

Read the full criminal complaint here

Photo showing Boston Marathon bombing suspect Dzhokhar Tsarnaev fleeing scene of bombing — David Green

This photo shows Boston Marathon bombing suspect Dzhokhar Tsarnaev, lower left wearing white cap, fleeing the scene of bombing.