A bloody massacre inside of a Newtown, Connecticut elementary school Friday morning has entered the record books as one of the worst mass shootings in the history of the United States.

Authorities say a gunman murdered more than two dozen people, mostly children, inside Sandy Hook Elementary School early Friday.

In all, state police say at least 27 people, including the shooter, died as a result of the gunfire. The shooter’s mother, Sandy Hook kindergarten teacher Nancy Lanza, has been confirmed by the authorities as one of six adults killed during the rampage that claimed the lives of 20 children. Friday afternoon, State Police Lieutenant J. Paul Vance announced that one adult was also found deceased at a secondary crime scene, bringing the total number of fatalities to 28 by midday.

Compared with statistics for similar incidents, the Newtown rampage has become the second-deadliest school shooting in US history and one of the worst crimes of its kind the country has ever seen. Sadly, it is not an isolated incident.

Friday’s massacre in Newtown is but a single example of what the Brady Campaign to Prevent Gun Violence says happens all too regularly. According to the organization, the United States has seen around 20 mass shootings every year since 2005.

“Another day, another horrific shooting eating away at our collective peace of mind,” Brady President Dan Gross wrote on the group’s Facebook on Friday. “We are better than this this. What matters is not what we do after the sensational tragedies. It's what we do between them – to make the voice of the American public heard.”

Aurora, Colorado, July 20, 2012

Suspect James Holmes opened fire during an opening-night screening of The Dark Night Rises, killing 12 people and injuring dozens of others in what US President Barack Obama called a “horrific and tragic” event.

Tucson, Arizona, January 8, 2011

A schizophrenic person killed six people and injured more than a dozen others, including a congressional lawmaker, outside of a supermarket. Jared Lee Loughner has been sentenced to life in prison for an act that almost killed Rep. Gabrielle Giffords (D-AZ)

Fort Hood, Texas, November 5, 2009

U.S. Army Major Nidal Malik Hasan is alleged to have killed 13 people after he went on a shooting spree at the busy US military base in the Lone Star State. He faces dozens of charges and could be sentenced to death if convicted during a court-martial.

Virginia Tech, April 16, 2007

Still the most deadly school shooting in US history: Student Seung-Hui Cho killed 32 people using a Glock 19 and a Walther P22 firearm before committing suicide. Friday’s massacre in Connecticut is the second-worst in US history behind Virginia Tech.

Littleton, Colorado, April 20, 1999:

Students Eric Harris and Dylan Klebold killed 12 classmates and then themselves inside of Columbine High School. Until Virginia Tech nearly a decade later, it was the worst school shooting in the country’s history aside from the notorious 1966 massacre waged from University of Texas clock tower.

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