Grouping Clusters by center point distances

Well I figured out the issue in my earlier post but now I want to try and group these points.  I have the groups of points now split into two lists which are acheived by taking the distances between those crimes and which ever police station is closer.  Now I want to take those two groups and cluster them based on the distance between each of the circle's midpoints to every other circle's midpoints in that list.  I saw a few examples, like the Proximity by list thread on here, but there was too much extra information in it.  I tried using the proximity 2d component and it works sort of I guess but not what I really would like to see it do. 

In the attached image are my two groups of points and the clusters I acheived with using the proximity 2d component.  I'm assuming since I can't loop anything that I would have to evaluate each individual point to every other point until all have been evaluated?  Then could I say; "If the distance between the points>20 cluster those points and move on?" 

Not really sure how to tackle this one, I did look up clustering analysis but I don't have the time to run this information through programs I have no idea to use.  I attached the grasshopper and rhino file as well so hopefully someone can help me out.  Thanks everyone.