The Sheriff makes crime data for Part 1 and Part 2 crimes available for download from this site: http://www.lasdhq.org/sites/CAASS/desc.html.
There are two sets of files: the last 30 days of data, as well as historical yearly data files for 2007 – 2011.
The actual locations have been slightly moved in order to de-identify specific locations – addresses and locations are now in the block range but not at the house.
This data covers areas of the Sheriff’s jurisdiction – which is not the entire County (for example, Los Angeles Police Department – LAPD – crime data is not included). But it is still a very large set of data.

[...] Crime rate by location is available by contacting a local Sheriff’s Department or through Los Angeles Country GIS Data Portal. Safety does not only mean the outside of a location but it also means the inside. The building [...]