Arizona police officers are required by the Arizona Police Officer Standards and Training board to complete continuing training on an annual basis. Police continuing training has traditionally been offered as lecture-based classroom training. Online training offers an alternative method of providing training. The purpose of this study was to compare the effectiveness of an online version of a police training class to a classroom-based version of the same course. Participants consisted of sworn police officers employed by the Phoenix Police Department and taking the department's Domestic Violence Investigation (DVI) course. The study compared student learning outcomes between the two course versions, as well as student attitudes and perceptions of training. The study utilized a descriptive research design with a mixed methods approach. Research questions investigated the attitudes and perceptions of participants, compared student learning outcomes between the two course versions, and asked whether educational level and previous experience with online learning was linked to positive learning outcomes in the DVI course. Quantitative data consisted of demographic questionnaires, a 45-question assessment of the likelihood of success in online learning, a 10-question pre-test, and a 10-question post-test. Qualitative data was obtained through interviews with six participants who had taken the DVI course. The results of the study indicated participants in the online version of the DVI course performed as well or better on the post-test than their counterparts in the classroom. Participants interviewed for the study enjoyed the online presentation of the course, and supported the development of additional online training options within their department. Positive student learning outcomes for the online DVI course provide support for the development of online police training programs. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]