Same shirt on both pictures Some sort of emblem on the left side of his chest.
That guy looks rather white, European maybe even.
The pics seem to show the same perp, in different locations, (same clothing, left-handed) so only one individual pictured so far.
Also carrying a similar rucksack, which could be carrying more ammo or a suicide device for when he gets cornered?
And, of course, every shooter has an assault rifle...