"scrot" is listed in the package database and apparently available using "pacman -Ss scrot", but attempted install throws error:
error: failed retrieving file 'scrot-0.8-7-armv7h.pkg.tar.xz' from mirror.archlinuxarm.org : The requested URL returned error: 404 Not Found
EDIT: solved, my pacman -Syu from yesterday already out of date.