"We might have been able to apprehend those [shooters] earlier," Keefe said.
Emergency responders who pushed for the statewide alert say that people who attack law enforcement officers pose an elevated threat to the public.
"We've got so many alerts out there, and we have to be judicious in how we implement these," said Summit County Sheriff Dave Edmunds. "But if you've got someone who's willing to take a shot at a police officer ... you've got someone who is capable of doing anything to the community."
The alert will activate the digital roadside signs now used for Amber Alerts, said Paul Murphy, spokesman for the Utah Attorney General's Office. It also sends notifications to other law enforcement agencies, ports of entry and the news media and may trigger a reverse-911 call.
It will only be used if an officer has been killed or seriously injured; if the suspect is an imminent threat to others; if police have enough information to help the public identify the suspect, such as a vehicle tag and personal description; and if notifying the public could avoid further harm or help police make a faster arrest.
Nine other states have Blue Alerts, and six more are considering similar systems, Murphy said.
Deputy Fox was shot and killed during a 1 a.m. traffic stop on Jan. 5, 2010. The suspect, Roberto Miramontes Roman, 38, fled to Salt Lake City and then to Beaver, where Roman was arrested with a friend who helped him flee. Roman is awaiting trial in 4th District Court on a charge of capital murder.
Deputy Harris was shot and killed Aug. 26, 2010, near Fredonia, Ariz., while tracking burglary suspect. Scott Curley, 23, was captured after a five-day manhunt and is awaiting trial in Arizona on a charge of first-degree murder.