When Jose Ines Garcia Zarate, an illegal immigrant who had repeatedly been deported, was acquitted Thursday of killing an American citizen, Kate Steinle, President Trump denounced the verdict as a "complete travesty of justice."

Related: Trump: Kate Steinle verdict more reason to 'BUILD THE WALL!'

The anger people feel over this acquittal contains an echo of the fury felt when a grand jury refused to indict the Ferguson policeman who shot and killed Michael Brown, in that it is stoked by a sense of systemic injustice, and a breakdown of law and order. In the case of Brown, the context was police mistreatment of young black men. In the case of Steinle, the context is lax enforcement of our immigration laws and sometimes out-and-out flouting them.

Steinle died in her father’s arms after Zarate shot her. His story changed over the course of the investigation, but he fired the gun in public, either at a sea lion or out of sheer recklessness, killing Steinle. But a jury convicted Zarate only on weapons charges.

Related: Arrest warrant issued for illegal immigrant acquitted in Kate Steinle murder trial

Whatever the injustice of the verdict in this case, it is right that our Constitution leaves such questions in a jury’s hands. But there is still the broader, deeply frustrating, not to say enraging, context. The jury cannot acquit our immigration system or cities that declare that they won't enforce our immigration laws and will interfere try to hobble federal authorities who try to enforce them.

There is no solid evidence that illegal immigrants are especially likely to be criminals. But that does not change the fact that sanctuary cities do great damage to the rule of law. Whenever a criminal illegal immigrant like Zarate commits a crime, it is always a crime that didn’t have to happen, because the perpetrator should not have been in the country.

Zarate was a career criminal who had repeatedly reentered the U.S. illegally. He had been slated for deportation before federal authorities sent him to San Francisco to face trial for an old drug charge. That charge was dropped, and the sanctuary city’s sheriff released him from jail rather than handing him back to the feds for deportation.

As Attorney General Jeff Sessions put it, Zarate “would not have been on the streets of San Francisco if the city simply honored an ICE detainer.” One seldom has the opportunity to see such a clear cause-and-effect relationship between a policy and a terrible outcome. If San Francisco’s sanctuary city policy hadn’t protected Zarate from deportation, Steinle would still be alive. States and cities that harbor criminals are deliberately endangering their own populations so they can strike attitudes on what they fatuously believe is the moral high ground.

There is no simpler problem in America to solve than the question of crime by convicted criminal illegal aliens. There is the one-size-fits-all answer. Remove them, and throw any leader out of office who cannot grasp this obvious requirement of public safety.