Unless your jurisdiction has a law specifying a minimum passing distance, there may me little the police can do. An inch may be as legal as ten feet.

As another member already indicated, if this is a repeated occurrence with certain individual motorists, it is much more of a legitimate complaint. Keep in mind that in some places, riding in the street is not socially acceptable, and bicyclists are expected to yield the whole road to motorists, no matter what the law says.

I see you are a newbie. Welcome to Bikeforums! Now, note that you posted this in General Cycling. Most members of Bikeforums to do not look at all the forums here, but concentrate on their areas of interest. Your topic falls under Advocacy and Safety; take a look there, and you will find discussion of this kind of stuff regularly.