President Barack Obama on Friday morning condemned the shootings as a "vicious, calculated and despicable attack on law enforcement."
And, in a familiar pivot, he also made reference to the dangers of guns.
"We also know," he said, "that when people are armed with powerful weapons, it makes shootings like this more deadly and more tragic."
Back in January, Obama -- frequently foiled by congressional opponents on this issue -- decided to go it alone, unveiling a series of executive actions
designed to help stem the violent epidemic. But even in the aftermath of the massacre at a gay nightclub in Orlando last month, the worst mass shooting in U.S. history, the partisan gridlock remains.
On at least six occasions in the last 100 years, Congress and the White House have come together and forged significant overhauls to federal gun law.
But in the more than two decades since President Bill Clinton signed the since-expired "Assault Weapons Ban," efforts to further restrict the sale and ownership of even the most powerful firearms have fallen flat.
As a primer, here's a look back at the evolution of gun law in America.
1934, 1938: Roosevelt cracks down on Capone and Co.
Legislation was drafted and passed in 1934 to impose new criminal penalties, along with regulations and taxes, on the machine guns and sawed-off shotguns preferred by the era's most notorious gangsters, largely in response to the bloody gun violence carried out by the likes of Al Capone and Bugs Moran.
Congress added to the National Firearms Act with another round of new laws four years later. The Federal Firearms Act of 1938 put restrictions on the interstate guns and ammunition trade. It required, in many cases for the first time, for dealers to register themselves and keep records of their transactions.
1968: For John, Robert and Martin
On October 22, 1968, President Lyndon Johnson signed the next big gun reform law, in the aftermath of three high-profile, violent deaths.
The initial push was prompted by the 1963 assassination of President John F. Kennedy. Lee Harvey Oswald used a mail-ordered rifle to kill the president as his motorcade passed through Dealey Plaza in Dallas. The subsequent assassinations of Martin Luther King Jr. on April 4,1968, and Robert F. Kennedy two months later fast-tracked the bill, which introduced stricter licensing and registration standards, a ban on the sale of guns and ammunition to felons and those deemed mentally incompetent, and new regulations on interstate sales, like the transaction Oswald used to obtain his weapon
The law also installed new regulations on so-called "destructive devices," including deadly gases, bombs, grenades, rockets and missiles, and set the stage for the birth
of the Bureau of Alcohol, Tobacco and Firearms in 1972.
1986: Reagan's compromise
President Ronald Reagan signed
the much debated "Firearm Owner's Protection Act" on May 19, 1986. The new legislation -- a mixed bag of new standards and regulations -- was the product of long held negotiations among lawmakers from both parties and gun lobbyists.
Most notably, the law banned the future sale of any fully automatic weapons, or machine guns, to private purchasers.
But it also included some major victories for the National Rifle Association and gun rights activists, who had long complained about overzealous enforcement of the Gun Control Act. The law also prohibited the creation of a national firearm database and allowed gun owners to pass freely through states with stricter controls provided their weapons were locked away or unloaded.
1993: The Brady Bill and background checks
Named after James Brady, Reagan's press secretary who was shot in the head during an assassination attempt on his boss 1981, the law required federally licensed dealers conduct background checks on handgun purchases.
The bill, signed
by President Bill Clinton in 1993, initially called for a five-day waiting period. But that requirement was phased out when the FBI launched its National Instant Criminal Background Check System in November 1998. According to federal statistics
, NICS has been used to conduct more than 225 million checks.
In a New York Times op-ed entitled, "Why I'm for the Brady Bill," Reagan wrote
about the incident that came within inches of killing him just 69 days into his presidency.
"Four lives were changed forever, and all by a Saturday-night special -- a cheaply made .22 caliber pistol -- purchased in a Dallas pawnshop by a young man with a history of mental disturbance. This nightmare might never have happened if legislation that is before Congress now -- the Brady bill -- had been law back in 1981."
1994: Clinton signs the Assault Weapons Ban
The next year, Reagan and two fellow ex-presidents, Gerald Ford and Jimmy Carter, signed a letter
endorsing a new round of legislation that banned the manufacture, possession and sale of certain combat-style weapons. It also limited the size of the magazine that feed ammunition into those heavy firearms.
Commonly referred to as the "Assault Weapons Ban," the law expired in 2004
during the George W. Bush administration and has not been renewed. The most recent reauthorization attempt was sponsored
by Rep. David Cicilline, a Rhode Island Democrat, and introduced in the House on December 16, 2015. During Obama's presidency, Congress has consistently resisted any attempts bolster gun control laws.