Which preposition to use with stockstill

for Occurrences 1%

If the mind requires but the tenth of a second to form an impression, I must have stood there stockstill for several seconds while I seized the ropes for support and stared.

in Occurrences 1%

"If a man works with a plow instead of a screwdriver, it doesn't follow that his mind is as vacant as a cow that stands stockstill in the middle of the road to show you that you can't fool her into thinking that radiators are good to eat.

Which preposition to use with  stockstill