Missouri soon will have a system to notify the general public when a law enforcement officer is killed or injured.Patterned after the Amber Alert system for missing children, the so-called “Blue Alert” law was signed Thursday by Gov. Eric Greitens, who had championed the idea.

The measure was part of a package of crime-related changes to state law approved by members of the House and Senate in May.

In addition to the Blue Alert plan, the new law creates the crime of illegal re-entry. Those who are deported from the United States for committing a crime and then return and commit a felony would also be guilty of illegal re-entry in Missouri.

The offense would be a class C felony, punishable by three to seven years.

The measure also adds museums that cater to children under 18 to the list of public places where sex offenders are banned.

The Blue Alert provisions are designed to promote public safety and protect police officers. When the law goes into effect, Missouri will be the 28th state to adopt such a program, according to U.S. Department of Justice figures.

The measure also enhances penalties for assaults on law enforcement officers.

“We must stand up for those who stand guard for us,” Greitens said in a release.

Greitens signed the measure at a St. Louis County police site in Pagedale. Among those who were there to witness it were Ballwin Officer Michael Flamion and St. Louis Officer Tom Lake, who were both badly wounded in on-duty shootings.

The changes come partially in response to the unrest in Ferguson after the shooting death of Michael Brown by Ferguson police Officer Darren Wilson in 2014.

The legislation is Senate Bill 34.

By Kurt Erickson | St. Louis Post-Dispatch