Life is Strange: Before the Storm

On the school yard go left to the swimming class entrance. On the right wall outside the entrance is the location for the optional graffiti #5.

Here is my complete video guide for all optional graffiti in Episode 1.

All optional graffiti are immediately saved. You can replay Episodes (Collector mode) to find your missing graffiti. There are always 2 graffiti which you can spray, it doesn't matter which one you spray.

00:08 - Optional Graffiti #1 (Recreational Vandalism)
00:56 - Optional Graffiti #2 (I See U Saw)
01:34 - Optional Graffiti #3 (The Last Unicorn)
02:22 - Optional Graffiti #4 (Home Unimprovement)
03:44 - Optional Graffiti #5 (Rock Idol)
04:36 - Optional Graffiti #6 (Dramatis Personae)
05:23 - Optional Graffiti #7 (Mulligan Stew)
06:36 - Optional Graffiti #8 (Pioneer Spirit)
07:20 - Optional Graffiti #9 (Face Your Anger)
08:10 - Optional Graffiti #10 (Lucid Writing)

This achievement is earned for finding optional graffiti #5. If missed on the first run, you can choose the episode from the main menu and select "Collector Mode". Now, you can use a scene select option to browse the locations and choose the area you need.

The following collectible can be found after being dropped off at school. Before progressing, go to the left, behind the outdoor stage and place graffiti on the outside wall near the door.
[2:50] - Optional Graffiti #5