The bottom picture is not very clear since I took it with my phone, but it is of a few lines in a woman's handwriting. When I remember to bring my camera along, I can take some clear photos and hopefully produce a transcript of what each line says. The gist of the writing seems to be about drugs, specifically marijuana. I could, however, be reading way too far into things. That isn't unusual for me.
The really interesting thing about this sample, aside from the fact that it seems to be about drugs and is in the creepy alley, is that it is written much higher than the reach of an average person.