The second guy (1) looks shorter than Suspect #1, (2) has a reddish hat, whereas Suspect #1 had a dark blue or black hat and (3) has a tan lining on his hood, whereas Suspect #1 has a blue lining on his hood.
Next to the guy in back is a runner or joggers 3 wheel stroller with the maroon or red canopy folded back. Has a green blanket in it or a kid wearing something green. Suspected bomber next her has his right hand up and is in front of his shoulder. Lady in black to his left is slightly in front of him with right hand swinging and happens to be in front of his crotch area. It appears that he zipped his black coat all the way up around his neck. Maybe to hide something? (wounds, blood, etc)