While we struggle to find common ground on sensible ways to reduce gun violence, we must not become blind to potential unintentional harm, such as stigmatizing every troubled teenager.

In the case of Parkland, Florida, shooter Nikolas Cruz, it’s hard not to wonder why warning signs weren’t enough to stop the 19-year-old before he killed 17 people at Marjory Stoneman Douglas High School. The FBI had been warned. Multiple police departments were warned. School officials tried a variety of methods to deal with his disturbing behavior.

Cruz had threatened fellow students, allegedly put a gun to a person’s head and posted online threats using his real name. More than one person who knew him thought him to be a real threat and believed it so fervently they took the “See something, say something” mantra to heart.

“I’m going to be a professional school shooter,” Cruz said in a comment on YouTube.

That’s why it’s tempting to use Cruz’s example to increase the surveillance of and harsh punishment for troubled teens who say and do disturbing things. No school district wants to be the site of the next mass shooting. But the Parkland case shows how these difficulties unfold over several years, beginning when students are young. But these questions and debates can be taken too far, as happened in the aftermath of the 1999 shooting at Columbine High School. Zero-tolerance laws sprang up everywhere and students who weren’t real threats were caught up in the overreaction, including an infamous case of a little boy suspended for eating his Pop-Tart into the shape of a gun.

A 2013 Broward County School board policy, the Promise Program, that encouraged the “least punitive means of discipline” — warnings, conflict resolution programs, etc., instead of immediate arrests — is now being debated in the state and cited by some as the reason the shooting was not prevented. But it would be a mistake to respond to this shooting by making the lives of already-troubled kids worse instead of helping them.

Most troubled kids don’t shoot up schools, even those who post ugly messages on social media. The mentally ill are more likely to hurt themselves than others. Further stigmatizing wayward youngsters will lead to more false positives for law enforcement to investigate. It’s akin to looking for a needle in a haystack by first adding more hay. We must try to prevent as many shootings as we can. That starts by not making the task more difficult than it already is.

The Charlotte Observer (Charlotte, N.C.)There are a few quotes and phrases that are so American — and so anodyne -— that they amount to a kind of bipartisan lexicon, cited with equal fervor by Democrats and Republicans alike.For more than a half-century, the litany has also included a phrase popularized by President John F. Kennedy: “A nation of immigrants.” Time and again, presidents and leaders of both parties have invoked those four words to lionize the contributions immigrants have made to the U.S. In 1981, for instance, Ronald Reagan invoked it: “Our nation is a nation of immigrants. More than any other country, our strength comes from our own immigrant heritage and our capacity to welcome those from other lands.”Why, then, has the U.S. Citizenship and Immigration Services, which issues green cards and citizenship documents, deleted the phrase from its mission statement? Agencies are free to revise their mission statements, of course. And the previous mission statement was not exactly poetry. But when the person in the Oval Office routinely employs nativist rhetoric, scapegoats foreigners, seeks lower levels of immigration, and makes it more difficult to obtain green cards and visas, it is nearly impossible to see the deletion as mere coincidence.And while Trump may be a lost cause, Republicans ought to speak out against the nativism he continues to display on a regular basis - if not to defend historical truth and American values, then at least to prevent further damage to their party’s reputation.

Bloomberg News