The main source of international data on crime is the United Nations Office on Drugs and Crime. Most of the data is included in reports which are downloadable as .pdf files, although some Excel tables are available.
The United Nations Office on Drugs and Crime (UNODC) at www.unodc.org makes most of its data available only in .pdf format. The annual World Drug Report on Illicit Drugs (available annually since 1997) can be downloaded at http://www.unodc.org/wdr2014/ . International Statistics on Crime and Justice can be downloaded from http://www.unodc.org/unodc/en/data-and-analysis/statistics/data.html which also provides access to some tables which can be downloaded in Excel.