as of scrot, open/edit .config/openbox/lxde-pi-rc.xml

replace scrot with (single line)
scrot -q 1 '%Y-%m-%d_%H-%M-%S_$wx$h_scrot.png' -e 'mv $f ~/Pictures/Screencaps/' ,or whateverYouLikeDir
and you have a handy screenshot dairy preventing scrot from overwriting and cluttering up the home dir.