Eventually during the mission Redlight, Greenlight, you will make your way through an arcade and will go into a shop called “Video”. Once here there will be loads of enemies in the area so take them all out to avoid distractions. Now you can start shooting the targets that are all over the place. I’ll go over the targets that I shot.
First target is in the window sile of the Sports Emporium shop, targets 2-5 are by the arcade sign around the cars and on the building, that’s left of where you’re standing. Target 6 is above the “The Red Army Coming Soon” sign. Targets 7-9 are inside the cinema. Target 10 is on the window sile just outside the cinema. Target 11 is in burger town behind the counter. Target 12 is behind the railings next to the stairs. Targets 13 – 14 are in the drinks bar. Target 15 is in the television shop.
If you are still struggling, feel free to use this video as a reference.
Hope this helped.