Equipment used in a crime is a clue to solve cases. Cars are often used in crimes for transportation. Security cameras are set in everywhere of downtowns. Drive recorders are set in many cars in Japan. Security cameras and drive recorders can record an image of a license number plate. However, the license number plate is often recorded in a small part of the image. It is needed to enlarge the image to read. However, the enlarged image is in low-resolution and blurry. Therefore, edges of the image are not clear. It is difficult to read the number plate from the low-resolution and blurry image. Machine learning has been used to identify blurry letters in an image. Performances of machine learning method change depending on classifiers. In this paper, performances of five classifiers for identifying the license number plate were compared. The proposed research can potentially contribute in solving criminal cases.