You should report these things. Otherwise the police will not know if it’s a rash or uptick. You can report minor property crimes online now so you if you feel the crime is too minor to call 911 but still want it on record, you can do it: http://mpdc.dc.gov/mpdc/cwp/view,a,1242,q,568970.asp
I did it for a minor theft. It was easy and someone called me for additional information the next day.