The document summarizes an article by Charles Klahm and Rob Tillyer that reviewed 23 studies on police use of force published between 1995-2008. It found significant issues with the available research. Variables like suspect and officer characteristics and encounter details were examined, but results often conflicted. Comparisons between departments lacked consideration of their differences in demographics and policies. More rigorous research is needed that uses standardized definitions and accounts for department variations to improve understanding and inform policy reforms.