NORTH KANSAS CITY, Mo. — On Tuesday, the Missouri State Highway Patrol issued a Blue Alert in North Kansas City.

Troopers were searching for a gray Ford Focus driven by a white male who shot and seriously injured an officer.

As phones and television screens across the metro sounded the alarm, the Blue Alert prompted questions of what it meant, as it is less common than an Amber Alert.

Amber Alert

An Amber Alert is issued when someone under the age of 18 is abducted and police believe there is a credible threat of serious bodily injury or death.

The child’s information is then shared with National Crime Information Center and law enforcement notify MSHP to issue the alert.

Blue Alert

A Blue Alert is issued to notify law enforcement agencies, news agencies, and the public about suspects who have killed, seriously injured or pose an imminent threat to police.

Once activated, the alert will will go out to via media, Missouri Department of Transportation and Missouri Lottery. A public information officer will be in charge of media questions.

Congress passed the Rafael Ramos and Wenjian Liu National Blue Alert Act, in honor of two New York City officers who were ambushed and killed in 2014.

The act established a network across the country to give early warnings of threats to police officers.

Silver Advisory

A Silver Advisory is issued to notify media and the public about a missing person over the age of 60.

For the advisory to be activated, a legal custodian of the person must submit sufficient information to local police, who will in turn notify the highway patrol.