Monday Morning Mystery!

Green marker found scribbled on wall: approximately 9 am
Green marker found scribbled on wall: 9 am
Green marker without lid: found: approximately 9:15 am
Green marker found without lid: 9:15 am
Suspect spotted with green marker on cheek: approximately 9:30 am
Suspect spotted with green marker on cheek: 9:30 am

Solved!

I do apologize for the poor quality of the evidence photos; but after all, most suspects don’t stand still.