how to filter a group of observation that their binary variable is always zero in r

I have longitudinal data set. I have a binary variable called engaging in illegal activity in a day. so there are people that they never engaged in a illegal activity and the variable is always zero for them. But there are poeple that some days they have envloved with the illegal activity so the variable is equall to one and some days they have not! Now I want to filter observations that their vaiable is always =0. if I use filter(illegal_activity==1), then I loose all of zeros! Unfortunatly I dont have another variable that use filter(illegal_activity==1 | ...)! Is there any other way to do that?