An item in Ed Sterling, "State Capital Highlights," in the Canadian [Texas] Record (August 28, 2008) offers some details about the Blue Alert system in Texas:
Executive order begins Blue Alert
An executive order signed by Gov. Rick Perry on Aug, 18 launched Blue Alert, a communications network to help track down suspects who flee after killing or seriously injuring federal, state or local law enforcement officers in the line of duty. Blue Alert, based on the AMBER [America's Missing: Broadcast Emergency Response] and Silver Alert [a national notification system that focuses on finding missing elderly people] programs, combines efforts of the DPS [Texas Department of Public Safety], the Governor's Division of Emergency Management and TxDOT [Texas Department of Transportation]. When Blue Alert is activated, the suspect's vehicle information will be displayed across the state primarily via TxDOT dynamic messaging signs and media broadcasts. Alerts instruct the public to contact local law enforcement via 911 if they have information related to the offense.
So the Blue Alert citizen notification system was initially a state program created by the governor of Texas, although it has subsequently broadened into a national network with the same goals as the original program.
This was not the first instance of "blue alert" as a warning system, however. Merriam-Webster Online offers this entry for blue alert:
blue alert : the second stage of alert (as for a threatened air attack or an approaching storm) during which emergency preparations are carried out according to plan ; also : the signal for this — compare RED ALERT ["the final stage of alert in which enemy attack appears imminent ; broadly : a state of alert brought on by impending danger"], WHITE ALERT "the all-clear signal after an alert ; also : the period of return to normalcy following an alert "], YELLOW ALERT ["the preliminary stage of alert (as when hostile or unidentified aircraft are nearing a defended area) ; also : the signal for this"]
Although MW Online doesn't provide a first occurrence date for this usage of "blue alert," book and newspaper database searches indicate that it originated in the United States during World War II. From "Santa Cruz Blacks Out on Army Alert Signal," in the Santa Cruz [California] Sentinel (January 4, 1942):
"The sound of the [unidentified] planes came from two directions, and then veered away. When it was not heard for 15 minutes the all dear signal was given."
Santa Cruzans who turned their radios to the wave length of the local police station flooded the Sentinel-News office with inquiries.
"The police radio said this was a blue signal; what does that mean?" was the commonest inquiry.
Police Chief Al Huntsman explained that the "blue alert" means that unidentified planes were heard, possibly headed in this general direction. The "red signal" calls for the blackout. A "white signal" is the equivalent of the all clear.
Similarly, from "28-Minute Blackout Last Night: Unknown Aircraft Near S. F. Bay Brings Alarm" in the Healdsburg [California] Tribune and Enterprise (February 19, 1942):
Healdsburg experienced its fourth blackout last night, the presence of unidentified aircraft flying in toward the San Francisco bay area resulting in a 28-minute blackout.
The red light, signifying the order for the blackout, flashed at local police headquarters at 9:07. The white—all clear—came on at 9:35.
The yellow alert was received here at 8:27, and was followed at 8:35 by the blue alert. The entire North Bay area was effected by the blackout, which was ordered by the Fourth Interceptor Command in San Francisco at 9:01.
And from "Los Angeles Has Air Raid Alarm Today," in the [Greencastle, Indiana] Daily Banner (February 25, 1942):
A blackout was ordered in the Los Angeles area at 2:25 a. m. (PWT) today.
All of Los Angeles county from Santa Monica to Pomona blacked out in response to the order of the Interceptor Command after a “blue alert” three minutes earlier.
Radio stations left the air at 2:27 a. m. throughout southern California with the exception of San Diego.
The first of these news stories appeared a little less than a month after the December 7, 1941, surprise attack on Pearl Harbor, Hawaii, by the Imperial Japanese Navy Air Service. Although dozens of matches for "blue alert" appear from January 1942 to November 1943, mentions of this particular warning system vanish from Elephind search results thereafter, through the end of the war.
They reappear in the early 1960s in the context of Civil Defense warning systems designed for use "in case of enemy attack"—most particularly, one would imagine, incoming nuclear warheads. For example, from "As We See It ..." in the Santa Monica [California] City College Corsair (October 4, 1961):
As members of the Santa Monica School District, City College students are expected to obey the instructions in the [Civil Defense] handbook. However, Buc students will be able to leave campus in case of a yellow alert signifying that attack is expected on short notice or a blue alert which gives "two hour" warning.
"Blue alert" jumps from military usage to industrial usage in the late 1970s, as we see in this instance from Christine McKelvie, "Power Cuts Possible,"in the [Steamboat Springs, Colorado] Steamboat Pilot (July 19, 1979):
Bristol said a load reduction plan has been developed. In the event electricity use must be curtailed, "interruptable service contracts" can be dropped.
The second step would be a "white alert" in which power suppliers would curtail in-house electricity use.
Step three is a "blue alert" during which YVEA and other power suppliers would contact large industrial and commercial consumers and ask for voluntary electricity curtailment that wouldn't jeopardize operations.
The fourth step, a "red alert," would affect households. The general public would be asked to reduce consumption.
And from Jim O'Connell, "Mines Could Face Energy Shortages," on the very same page of the very same issue of the [Steamboat Springs, Colorado] Steamboat Pilot (July 19, 1979):
The next four to six weeks are crucial in terms of summer peak loads.
Large users—especially the coal mines—will be notified if there is a "blue alert" to curtail any power use possible. If the problem exceeds an overall "red alert," phase four goes into effect and YVEA and other systems will arbitrarily shed loads.
...
"We don’t want to interrupt any central operation during a blue alert," he [Ev Bristol] continued. "Between large users and consumer cutbacks we could attain the 10 percent load decrease necessary to handle most emergencies."
Miscellaneous local warning systems have also ventured into "blue alert" territory. From Joe Milicia, "Five Injured in School Shooting" in the [Kent, Ohio] Daily Kent Stater (October 11, 2007):
Students hid in closets and bathrooms and huddled under laboratory desks after the principal announced a "Code Blue" alert over the public address system.
This last article appeared less than a year before the Texas Blue Alert program came into force by executive order of the governor, but it almost certainly has no connection to it. Rather, the Blue in Blue Alert seems to allude to the longtime identification of municipal police as "men [and women] in blue"—a connection reinforced by such popular-culture touchstones as Joseph Wambaugh's novel The Blue Knight (1972) and Errol Morris's documentary The Thin Blue Line (1988)—which, incidentally, involves the wrongful conviction of an innocent man for the murder of a police officer.
