William Terrill is an expert in police behavior, police use of force and police culture. Professor Terrill has worked with Phoenix Police Department to assess officer perceptions of firearm danger. Additionally, he has established a partnership between ASU and the Federal Law Enforcement Training Center (FLETC) in Glynco, Georgia, which provides internship opportunities for graduate students to gain valuable research experience.

Terrill is Interim Associate Dean in the Watts College of Public Service and Community Solutions, and Professor in the School of Criminology and Criminal Justice.

His work has examined several issues, including the variation in the use of force policies throughout the country, the various outcomes associated with the different policies, and numerous police observational studies in several cities.