A national group of law enforcement leaders meeting in Orlando this week renewed the reasonable call for mandatory background checks on all gun purchases, and it's time public officials in Tallahassee and Washington listened to them rather than the National Rife Association. The law enforcement groups don't write big campaign checks like the NRA, but their voices should be heard as they continue to plead for common sense in closing loopholes in screening gun buyers. Universal background checks will not wipe out gun violence, but they would be an important tool in limiting access to guns by those who already are not legally supposed to have firearms.Twenty years ago, the federal Brady Handgun Violence Prevention Act went into effect. The law requires background checks for guns purchased through federally licensed dealers. But screening of potential gun owners is not required for private sales, including transactions conducted online or at gun shows. Both Congress and the Florida Legislature have rebuffed every prudent attempt to close the loopholes.Members of the National Law Enforcement Partnership to Prevent Gun Violence said on Monday that expanded background checks are needed to keep guns out of dangerous hands. The group held a news conference at the International Association of Chiefs of Police annual conference in Orlando and cited a host of grim statistics about gun deaths as evidence of the need for expanded background checks. Guns are the leading cause of deaths for officers in the line of duty, and 41 officers have been shot and killed so far this year, an increase of 64 percent over 2013. Gun deaths in the United States rose to 91 per day in 2012, up from 82 per day a decade earlier.There is fresh evidence of the need for stricter control on gun sales. A shooting at a school in Washington state last week left three students dead, including the 15-year-old gunman. That same day, two sheriff's deputies in California were shot and killed in the line of duty.More than 1 million gun sales have been blocked as a result of the Brady Act, according to data from the Federal Bureau of Investigation. This confirms that screening works to keep guns out of the hands of buyers who should not have access to firearms. Yet an attempt to broaden background checks after the school shootings in Newtown, Conn., failed in Congress last year. But there is room for states to act. In Florida, legislators should close the loophole that allows private sales to slip through the cracks. Requiring and submitting to a background check for all gun sales is a reasonable protection and does not infringe upon the constitutional rights of legal gun owners.