When members of the Newtown police force entered the school auditorium where President Obama was about to speak, the crowd rose and applauded. The officers’ quick response to the carnage at Sandy Hook Elementary School had probably saved many young lives.

As the nation starts debating the lessons of Newtown, where a gunman killed 26 people, including 20 children, we should listen to what law enforcement officers have to say. Their message is clear and consistent: Tighten gun control laws.

The National Rifle Association likes to depict gun control advocates as liberal loonies who don’t respect or understand red-blooded, heat-packing Americans. But that characterization has always been unfair. The men and women who patrol our streets every day are the loudest advocates for greater restrictions on gun ownership.

Listen to James Johnson, the police chief of Baltimore County, Md., and the new chairman of the National Law Enforcement Partnership to Prevent Gun Violence: “America, we are not doing enough to keep guns out of the wrong hands. We are long past the point of saying ‘enough is enough.’ The mantra has grown old. It’s time to take action to keep firearms from dangerous people.”

No law can protect every child — or every cop — from a crazy person with a gun. But it’s absurd and even immoral to assert, as the gun lobby does, that because laws are imperfect, they are useless.

We don’t cancel speed limits or drunken driving laws, even though they are violated constantly. We make them tighter and enforce them better because we know they save lives. Not every life, but enough to make the laws worthwhile.

Police officers say the same thing about gun laws, and they should know. As the nation was focusing on Newtown, Conn., two police officers in Topeka, Kan., were shot and killed outside a grocery store. “It’s clearly beyond words,” lamented Topeka’s police chief, Ronald Miller. “It’s unspeakable … about why this is happening in America at this stage in our history.”

The police focus on several key issues, starting with the easy availability of military assault weapons, the kind used in Newtown and other recent massacres. They are especially alarmed by high-capacity magazines that enable shooters to spray 30 and even 100 bullets without reloading.

“It is ridiculous to argue that hunters or civilians who own weapons for self-defense need a 100-round drum magazine,” Johnson says. “As we have seen, people don’t stand a chance against this kind of firepower.”

Police Chief Robert White of Denver told the local website Westword: “Gun policies are absolutely critical. Assault weapons serve no practical purpose. You can’t use them for hunting. We’re not soldiers in a war abroad. I have a lot of questions about assault weapons.”

The second major area of concern for the police is faulty background checks. Under current law, those checks are required only when a gun is bought through a licensed dealer. But 40 percent of all sales are made at gun shows or through other private transactions and are entirely untraceable.

Chicago police Superintendent Garry McCarthy tells the Chicago Tribune that this huge loophole must be closed. He notes that one of his officers was shot with a gun originally sold in 1972 that got totally lost in the system. “Where has that gun been since 1972?” he asks. “And the problem is, they don’t have expiration dates. It’s not like milk. That gun from 1972 is just as deadly in 2012 as it was in 1972. We’ve got to do something about the flow of firearms here.”

Police chiefs are political creatures; they’ve been preaching this sermon a long time, and they know why the problem persists. “We talk about this constantly, and absolutely nothing happens,” says Philadelphia police Commissioner Charles Ramsey, “because many of our legislators, unfortunately, at the federal level lack the courage to do anything.”

He’s right about that, but there are small signs that Newtown might have some positive effect. A few lawmakers finally seem motivated to defy the NRA, which has followed the infuriating but effective strategy of opposing all restrictions on all guns at all times. Reasonable compromises are out there that won’t violate anybody’s right to defend his home or bag his buck: Ban assault weapons, or at least high-capacity magazines; extend background checks to all gun sales; improve the sharing of information among government agencies so that the mentally unstable or criminally inclined have a tougher time buying guns.

These measures won’t save every life, but they’ll save some, and that’s a deal worth making. Just ask the cops.

(Steve and Cokie Roberts can be contacted by email at stevecokie@gmail.com.)