A gunman opened fire on a crowded nightclub in Orlando early Sunday, June 12. He killed at least 49 people. The final death toll is not known, but this shooting is already the deadliest mass shooting in the history of the United States. (Monica Akhtar/The Washington Post)

In the grim statistics of terrorism in America, the shooting at a gay nightclub in Orlando early Sunday morning appears to represent the deadliest attack on U.S. soil since Sept. 11, 2001. It may also mark the doubling of the number of people killed in America by a terrorist motivated by Islamist ideology in the years since September 2001.

Before the attack in Orlando on Sunday, 45 people in the United States had died in jihadist terrorist attacks since 9/11, according to a database maintained by the New America, a Washington think tank. The think tank added 50 more deaths, a figure which includes the shooter, to its database Sunday because of the attacks in Orlando.

The shooter's ties to terrorism have not been fully established. U.S. law enforcement officials told The Washington Post that 29-year-old Omar Mateen called 911 and pledged allegiance to the Islamic State, also known as ISIS. The group has also claimed responsibility for the attack, but whether it in fact had any role has not been confirmed.

The New America database on deaths due to terrorism in the United States gathers information about violent extremist activity and separates incidents into several groups — including those motivated by jihadist ideology, such as that of al-Qaeda and its affiliated groups, and those driven by non-jihadist ideologies, such as right-wing and left-wing beliefs.

In recent years, domestic terrorism motivated by right-wing hate groups had been behind most deaths. But that changed with the massacre in San Bernardino, Calif., last December. The shootings in Orlando would alter the picture further, according to the New America.

Before Sunday’s shooting, the data showed, 45 people had been killed in the United States from terrorist incidents linked to violent jihadism since September 11, 2001, while 48 deaths had been linked to incidents of right-wing terrorism.

Including Sunday morning’s attack, here are the cumulative deaths caused by Islamist attacks and right-wing attacks over the past 13 years:


The addition of 50 fatalities — more than three times as many deaths as the next-deadliest terrorist attack, the one in San Bernardino in December — changes these figures substantially, as the tally below from New America shows.


New America

It is possible, however, that the attack in Orlando could represent both a hate crime against gay Americans — like those committed by right-wing extremists in other cases — as well as a terrorist attack motivated by jihadist ideology. President Obama today described the massacre at a gay nightclub in Orlando as an "act of terror" and an "act of hate." It's unknown the degree to which the shooter deliberately targeted gay people for slaughter.

New America's figures can change fairly quickly, since the total number of deaths due to terrorism in the United States is small and each attack can involve a large number of fatalities. Before the shooting in San Bernardino, right-wing extremists had killed nearly twice as many people in the United States as Islamist extremists had – 48 vs. 26. But the 14 deaths in the San Bernardino shootings, which New America ultimately classified as jihadist terrorism, transformed that tally.

In a description of the database's methodology, New America acknowledges that extremism is a subjective term. It says it has gathered data on any use of violence in the pursuit of political ideology, regardless of whether that ideology is considered to be mainstream in the United States.

For example, the list of right-wing attacks includes a 2004 Tulsa, Okla., bank robbery, because the perpetrators testified that they were stealing the money to buy weapons and carry out a “mission to revenge Waco.”

It also includes the 2012 shooting of six people in a Sikh temple in Wisconsin by a white supremacist, the murder of three people at Jewish institutions in Kansas City by a man with ties to the Ku Klux Klan, and the shooting of nine people at the Emmanuel AME Church in Charleston, S.C., by white supremacist Dylann Roof.

New America's count of deadly jihadist attacks includes the 13 people killed in a shooting at the Ford Hood military base in 2009, a beheading in Oklahoma by an Islamist extremist in September 2014 and the four people killed in the Boston Marathon bombing, among others.

But New America chose to exclude the Beltway sniper of 2002, for example, because "they said something about Osama bin Laden once, but they seemed to be losers who wanted to be the heroes of their own story," Peter Bergen, who directs the International Security Program at New America, said in an interview in December.

After the deadly shooting in an Orlando nightclub on June 12, some in politics pushed for stricter gun control while others asked for prayers. GOP presidential candidate Donald Trump ignited controversy with his tweets. (Jenny Starrs/The Washington Post)

Speaking on Sunday, several Republicans, including Donald Trump, referred to the Orlando attack as an incident of “radical Islamic terrorism.” Democrats, meanwhile, initially described the incident as a hate crime against the LGBT community and denounced loose restrictions on the kind of assault-style rifle used in the attack.

Either way, authorities were quick to condemn the act as terrorism. The local sheriff’s department said it would “certainly classify” the shooting “as a domestic terror incident,” while Florida Gov. Rick Scott (R) csaid the incident was “clearly an act of terror."

See also: 

In the modern history of mass shootings in America, Orlando is the deadliest

Orlando shooting: The key things to know about about guns and mass shootings in America

The gun used in the Orlando shooting is becoming mass shooters’ weapon of choice