In previous research, keystroke dynamics has shown promise for user authentication, based on both fixed-text and free-text data. In this research, we consider the more challenging multiclass user identification problem, in the case of free-text data. We experiment with a complex image-like feature that has previously been used to achieve state-of-the-art authentication results over free-text data. Using this image-like feature and multiclass Convolutional Neural Networks, we are able to attain a classification (i.e., identification) accuracy of 0.78 over a set of 148 users. Surprisingly, we find that a Random Forest classifier trained on a slightly modified version of this same feature yields an improved accuracy of 0.93.