More than 300 law enforcement agents from 46 agencies are looking for Scott Curley, who police say shot and killed Kane County Sheriff's Deputy Brian Harris, The Arizona Republic said Sunday.
Police said Curley, 23, killed Harris during a foot chase near the Utah-Arizona state line. Harris was helping police in Arizona's Coconino County look for a suspect tied to a school break-in in Fredonia.
Investigators said Curley, a Native American, allegedly opened fire with an AR-15 assault rifle when the chase moved into rugged terrain between Fredonia and Kanab, Utah. Police returned fire, but Curley escaped.
Kane County Sheriff Lamont Smith described Curley as a mentally ill and "delusional" troublemaker that has had several run-ins with his department and other agencies in the region.
The U.S. Marshals Service, the FBI and several police agencies in Southern Utah and Arizona are taking part in the search.