"Anytime that you have multiple shootings against American citizens on a highway, that's terrorism," Milstead said. "They're trying to frighten or kill somebody."
Police have been asking for the public's help in identifying a suspect, including putting messages on freeway billboards urging people to report suspicious activity. There is a $20,000 reward on the table for information leading to an arrest or indictment in the case.
Anyone with information related to any of these incidents is asked to call Silent Witness at either 480-WITNESS (948-6377) or 1-800-343-TIPS (8477). Spanish speakers may call 480-TESTIGO (837-8446). You also may submit your tip online.