Abstract This paper describes the University of Sheffield entry for the 2nd international plagiarism detection competition (PAN 2010). Our system attempts to identify extrinsic plagiarism. A three-stage approach is used: pre-processing, candidate document selection (using word n-grams) and detailed analysis (using the Running Karp-Rabin Greedy String Tiling string matching algorithm). This approach achieved an overall performance of 0.20 in the official evaluation with