Las Vegas massacre becomes America's 273rd mass shooting in 275 days

When a lone gunman opened fire on a concert in Las Vegas, killing at least 58 and injuring more than 500, it marked the 273rd mass shooting in America in the last 275 days.

That same day, three people were killed in a shooting stemming from a “physical altercation” in downtown Lawrence, Kansas. The day before that, a 15-year-old boy was killed in a shooting in Memphis, Tennessee. Three others were injured.

The Gun Violence Archive – an independent, online database of gun violence incidents in the US – defines a mass shooting as a single incident in which four or more people are shot. According to their records, there have been 273 such incidents in the US in 2017 alone.

This may be an underestimate, however, as another database, Mass Shootings Tracker, lists the number as 338.

And the current year is not an outlier: There were 383 mass shootings in 2016, and 358 in 2015, according to the Archive.

These numbers far surpass any other developed country in the world, according to research out of the University of Alabama.

Hannah Shearer, a staff attorney for the Law Center to Prevent Gun Violence, says this is because gun violence in general is more prevalent in the US than any of these other countries.

“The reason is just that the type of weaponry that are most commonly used in mass shootings just aren't available in other countries,” Ms Shearer told The Independent. “...That’s what contributes to disproportionate rates of mass violence in the US.”

Ms Shearer pointed specifically to the accessibility of semi-automatic weapons, or guns that can reload automatically, within the United States. Only seven states in the US currently ban such weapons.

Stephen Paddock, the man identified by police as the Las Vegas shooter, is said to have used automatic or semi-automatic guns in his attack. Police said he had as many as 10 weapons in his hotel room at the time.

Nevada law does not limit how many weapons an individual is permitted to buy.

The Las Vegas shooting has been named the deadliest in US history, surpassing last year’s record-breaking attack at an Orlando nightclub. That incident killed 49 people, and injured 58.

Ms Shearer said mass shootings have increased in both frequency and lethality in the last 10 years. It has been 13 years since the federal ban on semiautomatic weapons expired.

Gabrielle Giffords, a former congresswoman who was injured in a mass shooting in 2011, urged Congress take action on gun control on Monday.

“I am praying they find the courage it will take to make progress on the challenging issue of gun violence,” Ms Giffords said of her former colleagues.

She added: “Now is the time to take positive action to keep America safer. Do not wait. The nation is counting on you.”