The 20 Worst Mass-Shootings In United States History

The world is mourning the loss of 49 individuals after a tragic shooting at Pulse nightclub in Orlando, Florida. The incident that occurred on June 12th, 2016, is the worst mass shooting incident in the history of the United States. As I am sure you know, while this may be the worst, it is far from the only time there has been a mass shooting in America. Unfortunately, most of us have memories of the Sandy Hook shooting, the Batman theater incident, Virginia Tech or any of the other mass-shooting incidents that are also going to be detailed below.

The 20 incidents below are the worst mass-killing sprees in America's history. To put that in context, number 20 took the lives of nine people. In total, 339 people were murdered over the course of the 20 events below. The events range from moments in the 80s, like the infamous shooting up of a McDonald's in 1984, to of course the sad story that is still developing.

Below is also outlined what guns were used, how they were purchased and if there was any history of mental illness in the shooter. As well as this, you’ll learn just how these incidents ended (suicide, police shootout or otherwise), and the motives behind some of the worst incidents imaginable.

No matter what your stance on gun control is, I think it’s safe to say that when 49 people lose their lives just because they went out dancing, it’s a devastating moment in America’s society.


20 Dylann Roof – 9 Killed


Dylann Roof opened fire during a prayer service at the Emanuel African Methodist Episcopal Church. 9 people (all African American) died in the assault, including a state senator and a senior pastor. Dylann was quickly identified as being the main suspect and was taken into custody the following day. When asked about his motives, Dylann stated that he wanted to try and ignite a race war.

He purchased the gun using birthday money and it was reported that he was able to purchase the gun because of a lapse in the FBI Background Check System.

When investigators were doing their search, they discovered that Roof had several photos of white supremacy items and had written a manifesto that was anti-black.

He is currently potentially facing the death penalty and will have his trial start on January 17th, 2017.

Roof is currently only 22 years old, making him one of the youngest (but not the youngest) to commit these types of acts. While there were race implications, there was no terrorist affiliation associated with the attacks.

19 Chris Harper-Mercer – 9 Killed


Chris Harper-Mercer was 26 years old when he decided to shoot and kill 9 individuals at Umpqua Community College back in 2015. Several others were also injured in the attacks. Harper-Mercer was found to be in possession of 14 weapons, all of which were purchased legally. He had brought 6 of the guns with him to the shooting, and there were 8 more recovered at his residence. Like Roof, Chris had white-supremacy leanings and was described as being obsessed with guns.

Chris reportedly asked his victims what their religion was, and if they responded with Christianity, they were promptly re-shot.

Harper-Mercer was a former member of the U.S. Army but was discharged after only 5 weeks because he failed to meet minimum administrative standards. There were also reports that Harper-Mercer was extremely isolated and would often spend time with his mother at shooting ranges.

Prior to the shooting, Harper-Mercer had also been placed on academic probation and owed his university $2,021 by October 6th.

Harper-Mercer’s attack ended after he killed himself during a shootout with the police.

18 Michael McLendon – 10 Killed 


Michael McLendon killed 10 people back in 2009 in Alabama. Described as the Geneva County Massacre, Michael started his rampage by murdering and burning down the house of his Mother. Michael also murdered his maternal grandmother, two cousins, and uncle (among others). When looking for motives, investigators discovered that Michael was depressed about being unable to find work and was not pleased with the amount of support he was receiving from his mother. Looking at the list of victims, it’s clear he may have had some grudges with his family.

Michael’s shooting spree included a period of time in which he was driving around in his car, shooting at different people on the street.

6 people were wounded during the attacks, and three dogs were killed. Michael used a 12-Gauge Shotgun, a .38-Caliber Handgun, a Bushmaster AR-15 and a Soviet-Made SKS Rifle.

Michael was found by police with a self-inflicted gunshot wound. He was only 29 years old.

17 James E. Holmes – 12 Killed


Many people know about the Batman killer, but can you believe his shooting is only the 17th worst in United States history? Holmes killed 12 people and injured over 70 others after he opened fire at a movie theater in Aurora, Colorado. On top of using several guns, Holmes used gas/smoke canisters to help increase the level of confusion.

Holmes was arrested without incident and charged with 140 counts of attempted first-degree murder. He received 12 life sentences in prison with the possibility of parole, as well as an additional 3,318 years. He made a plea of not guilty by reason of insanity, which was accepted. As well as this, he was ordered to pay $955,000 in restitution to the state victim compensation fund, as well as to the victims.

On top of the massacre at the theater, Holmes had booby-trapped his apartment with explosives, but thankfully it was diffused by a bomb squad after Holmes admitted to it while in custody.

16 Aaron Alexis – 12 Killed


Aaron was a former member of the United States Navy but was honorably discharged in 2011. It was reported that Aaron had been cited for misconduct on at least 8 different occasions.

Aaron had access to a Remington 870 Express Tactical 12-Gauge Shotgun, and a stolen Beretta 92FS 9mm semiautomatic pistol. His shooting spree led to the death of 12 people at a Washington Navy Yard in Washington, D.C. The incident ended when police killed Alexis during a shootout.

8 other people were injured in the attack. Alexis had been reported to have been a victim of harassment, as well as hearing voices in his head. An FBI official after the attack stated that he believed Alexis was “under the belief that he was being controlled or influenced by extremely low-frequency electromagnetic waves."

Alexis had also battled insomnia, but the impact that it may have had on the day of the shooting is unclear.

15 Mark Barton – 12 Killed


Mark Barton started his murder rampage by attacking his two children (aged 12 and 10) with a hammer, unfortunately ending their lives. As well as this, Barton had taken out his second wife (his first wife was beaten to death, and while he was a suspect, Mark was not charged). There was a note left that stated “If Jehovah's willing I would like to see them all again in the resurrection to have a second chance. I don't plan to live very much longer, just long enough to kill as many of the people that greedily sought my destruction."

Barton then traveled to two day trading firms and opened fire. In total, Mark killed 12 individuals and injured another 13 before committing suicide. Barton was also a day trader and was apparently motivated by the fact that he had lost $105,000 in the past two months.

There were reports that Barton suffered from severe depression as well as paranoid delusions. While police were able to track down Barton, he committed suicide before they were able to reach him.

14 Howard Unruh - Killed 13


This may have happened over 60 years ago, but that does not make it any less tragic an event. Howard was a WW2 veteran who murdered 13 people (3 children) while out on a 12-minute stroll around his neighbourhood. The incident earned the nickname the Walk of Death.

Howard used a Luger P08 Pistol to commit the atrocities and was committed to an insane asylum after he was taken into custody. It was not without incident, though, as over 60 policemen were called to his house to try and bring him down. He was 28 years old at the time of the attack and passed away after a lengthy battle with illness at the age of 88.

Howard had allegedly grown paranoid about his neighbours until one day he snapped. “When I came home last night and found my gate had been stolen, I decided to kill them all."


13 George Banks - 13 Killed


At the time, Banks was responsible for the most fatalities by a single mass murderer in any state. It was 1982 when he decided to murder 13 people, 7 of which were children (5 of his own), including 4 of the children’s mothers.

While Banks attempted to plead insanity, he was convicted of 12 accounts of first-degree murder and sentenced to death. His sentence has been appealed several times, most recently in 2010, claiming a reason that George is too incompetent for execution.

George used a Colt AR-15 Semi-Automatic Rifle during his rampage. Prior to this, George was a former Camp Hill State Prison Guard but he was relieved from duty earlier that month and was evaluated for mental-health issues.

When looking for reasons as to why investigators discovered that George had previously told coworkers that “the world would soon be consumed by a race war and said he wanted to prevent the five children he fathered with the four white girlfriends from the torment and agony of racism.”

12 The Wah Mee Massacre – 13 Killed

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Back in 1983, Kwan Mak, Wai-Chiu Ng, and Benjamin Ng murdered 13 individuals at the Wah Mee Gambling club in Seattle.

Only 1 potential victim survived the attack and was able to help investigators discover who had committed the crime. The club itself was illegally run in Seattle by several wealthy restaurant owners and had high levels of security. Prior to the murder, the 3 men also robbed everyone present. While there were no specific guns that were known to be used, you can imagine these men came prepared.

Kwan Mak had made it clear that there could be no witnesses as he was easily identified by everyone in the room and was a known and trusted accomplice. While two of the men (Mak and Benjamin) were convicted of murder in 1983, the third individual went on the run in Canada. He was successful at staying out of trouble for several years, but he was eventually caught and deported back to Hong Kong in 2014.

11 Columbine Shooting – 13 Killed


When you think of mass-shootings in United States history, the Columbine Shooting may be the first one that pops into your mind (…at least before Orlando). Occurring back in 1999, Eric Harris and Dylan Klebold murdered 12 students and 1 teacher, and injured 21 others at Columbine High School.

The two men committed suicide when it was clear they were about to be arrested. Among the weapons used was an Intratec TEC-DC9, Stevens 311D Double Barreled Sawed-Off Shotgun, 99 explosives, 4 knives, a Hi-Point 995 Carbine and a Savage 67H Pump-Action Shotgun.

The incident led to a stricter school security system, as well as a general sense of panic on the potential role of violence in videogames, anti-depressant use and gun control. The two individuals (Mark Manes and Phillip Duran) who were charged with supplying the guns to the two teenagers was sentenced to six and 4 ½ years in prison.

10 Jiverly Wong – 13 Killed


Jiverly Wong was a former student of the American Civic Association immigration center in Binghamton, New York. He had dropped out a month prior, and on April 3rd, killed 13 people that were in the building. It was the worst mass killing event in the state of New York since 9/11 and also left 4 people injured.

Wong killed himself before he was able to be taken into custody. In total, he fired 99 rounds using a 9mm Beretta and a .45-Caliber Beretta.

One of his potential victims a receptionist, Shirley DeLucia, feigned her own death after being shot in the gut and was able to call 911 and help assist police during the attack.

When looking for motives, many people blamed Wong’s poor English skills that led him to feel degraded and disrespected, as well as the fact that Wong had lost his job and was struggling to find work.

9 Maj. Nidal Malik Hasan – 13 Killed


Nidal Hasan was a United States Army Medical Corps Psychiatrist. While this is a respectable job, his coworkers were concerned over his social isolation, how stressed he was, and that he generally seemed upset. In 2009, Nidal used an FN Five-Seven Pistol to murder 13 people, and injured 30 others in Ford Hood, Texas. At the time, the incident was described by the U.S. Senate as being the worst terrorist attack on U.S. Soil since 9/11. Malik was eventually taken into custody after a shoot-out with two officers. Malik was wounded in the incident and went into a coma, but eventually regained consciousness.

Despite his co-workers stating he was Anti-American, after investigation it was determined that there was no link to terrorist organizations for the attack.

Hasan may also have felt motivated by the fact that he was distressed about being deployed to Afghanistan later that month.

8 Patrick Sherrill – 14 Killed


Have you ever heard the expression of someone "going postal"? You can credit Patrick for that phrase. Patrick was a relief carrier for the post office, requiring him to work different routes on different days. This lack of stability in his job led reporters to discover that Patrick was an erratic, and easily irritable worker.

Patrick’s rampage lasted for 15 minutes and saw him attempt to kill 20 co-workers, 14 of which were fatally wounded. The incident ended after Patrick committed suicide. Patrick had been verbally reprimanded at work the previous day, and his fear of being fired could also have been a factor in the incident. One of his bosses who had reprimanded him was a clear target, but thankfully for him, he slept in that day and was able to avoid the shootings.

Patrick used two M1911 (.45 ACP) semiautomatic pistols and a Ruger (.22-caliber) semiautomatic pistol.

7 Rizwan Farook and Tashfeen Malik - 14 Killed


I suppose when you are married, you really do want to do everything together. For Rizwan and Tashfeen, that included attempting to bomb an Inland Regional Center in San Bernardino, California.

The banquet hall that was targeted had 80 people inside, 14 of which were killed and 24 more were injured. The incident ended when both culprits were shot and killed by police during a shootout following their attempted escape. There were also initial reports that there may have been a third shooter present, but that was originally discredited because only two firearms were recovered. As of February 18th, 2016, the FBI has come out and said they are not discounting the possibility that there was a 3rd shooter.

Barack Obama addressed the nation stating that this was in fact, an act of terrorism. While the two had no links to a terrorist organization, they were allegedly inspired by different foreign groups.

The attack was committed with two .233 AR-15-Type Semi-Automatic Rifles, Two 9mm semi-automatic pistols and pipe bombs.

6 Charles Joseph Whitman – 17 Killed


You may have heard about the infamous bell-tower shooter before, and not realized the person they were talking about was Charles Whitman. Charles started out his day by murdering his wife and mother, and then proceeded to camp out on a University of Austin watch-tower with a Remington 700 ADL (6mm), Universal M1 Carbine, Remington Model 141 (.35-Caliber), Sears Model 60 Semi-Automatic Shotgun (12 Gauge), S&W Model 19 (.357 Magnum), Galesi-Brescia (.25 ACP), a Luger P08 (9mm) and finally, a knife.

So needless to say, he came prepared. Over the course of the day, Charles killed 18 people and wounded over 30 others.

The incident came to a fatal end for Whitman when he was shot and killed by a police officer. A shootout is a scary enough thing to experience, I can only imagine it’s all the more intense when you’re climbing a bell tower to meet the killer!

5 James Huberty – 21 Killed


The world may seem like it was safer back in the 80s, but did you know about the mass shooter that shot up a McDonald’s in 1984? James killed 21 adults and children and injured 19 others. It was the deadliest mass shooting committed in the United states at the time.

Three days prior to the shooting, James had called a mental health clinic asking for an appointment, citing that he thought he had a serious problem. The clinic, unfortunately, misspelled his name and the phone call to confirm his appointment never came.

His wife stated that prior to the shooting, Huberty had talked about how society had had its chance, but now it was time to go and hunt humans.

Huberty’s wrath lasted for 78 minutes and saw him fire off 245 rounds of ammunition.

When asked about what it looked like on the day of the shootings, Dr. Thomas Neuman stated "It was like they had just stopped in time. All these bodies were lying around. Heads were slumped on the table ... the old man walking out the door was lying on the floor, donuts beside him. The two kids were dead by their bikes; the infant was dead in the arms of the people ... there were two burned hamburgers on the grill."

The incident came to an end when a SWAT sniper was able to have an unobstructed view of Huberty from the neck down. The shot severed Huberty’s aorta.

4 George Hennard – 23 Killed


As you can guess by the spot on the list, this is the 4th deadliest mass shooting in United States history. The incident occurred on October 16th, 1991 and started when George Hennard smashed his pickup truck into the front of a Lucy’s Cafeteria.

George then emerged from the car and started to shoot and kill anyone he could. Eventually, 23 people lost their lives, and 27 individuals were wounded. During the attack, George brandished a Glock 17, as well as a Ruger P89 pistol.

George engaged in a shoot-out with police, but was eventually wounded and was forced to retreat to a bathroom where he then committed suicide.

When looking for motives behind the attack, reports talked about Hennard’s apparent hatred of women. While men were also killed, women made up 14 of the 23 victims. George was also unemployed and was described as being angry and withdrawn from society.

The incident lasted a little over 12 minutes.

3 Adam Lanza – 27 Killed


While this is not the deadliest mass shooting in United States History, I don’t know if there was one on this list that made people’s hearts sink more than the awful tragedy at Sandy Hook. Adam Lanz murdered 27 people, including 20 children that were between the ages of 6 and 7. Prior to the attack, Lanza murdered his mother at his home.

Used in the attack was a Bushmaster XM15-E2S, and a .223 Caliber Semiautomatic Rifle.

A detailed transcription of the event can be found online, but the details are far too graphic to start talking about here.

Lanz committed suicide when he realized that first responders were starting to arrive on the scene. There was no terrorist motivation for the attack, and investigators have failed to find a reason as to why he targeted Sandy Hook Elementary.

Lanz had been diagnosed with Asperger's and was also being treated for an obsessive-compulsive disorder. His father also had concerns that his son may have been suffering from schizophrenia.

At home, Lanz had cut off communication with his father and brother and at one point in time was only communicating with his mother through email. Lanz also had an apparent obsession with previous mass shooters, and there are definitely people that feel he used incidents like the Columbine shooting for inspiration.

2 Seung-Hui Cho – 32 Killed


Until earlier this week, Seung-Hui Cho had committed the worst mass shooting in United States History. Many of us can remember where we were back in 2007 when it was reported that there was a shooter at Virginia Tech.

The shooter, Cho, was a student at the university and was only 23 years old at the time of the shooting. It lasted for over 2 hours and saw 32 people die and 17 others get injured in the attacks.

As a student, Cho was described as being very abnormal and often would write down things that were referencing violence. In middle school, Cho was diagnosed with a severe anxiety disorder, as well as serious depression.

Many people criticized the failure to get Cho the help he needed, for the shooting. Cho was able to get his hands on a Glock 19 pistol and a Walther P22 pistol. Both guns were purchased legally after Cho was able to pass the background checks required.

Reporters found a note left by Cho that attacked the “rich kids” and “deceitful charlatans” and stating that they were who caused him to do all of this.

It was also reported that Cho had been practicing at a firing range for months prior to the shooting, clearly showing that this was far from a crime of passion but was instead a deliberate and planned event.

1 Omar Siddiqui Mateen – 49 Killed


It is with a heavy heart that we have to talk about the fact that the worst shooting in United States history happened on June 12th, 2016. Omar Siddiqui Mateen opened fire at Pulse, a crowded gay nightclub in Orlando. Omar was equipped with an AR-15 Style Assault Rifle as well as a handgun.

50 people (including the attacker) have been confirmed dead from the attacks, with 53 more people being injured.

It was initially reported that Mateen called 911 prior to the shootings and pledged allegiance to Abu Bakr Al-Baghdadi, who is the leader of the Islamic State.

In 2013, Mateen had been questioned on two occasions for potential links to terrorists, and in 2014 he was investigated for a link to an American suicide bomber.

That being said, Mateen’s father opened up about how in the past his son had been seen getting infuriated at the sight of two men kissing, and stated that “We are in shock like the whole country, this had nothing to do with Religion.”

Mateen’s ex-wife, who divorced Mateen in 2011, described him as being an unstable person “He beat me. He would just come home and start beating me up because the laundry wasn't finished or something like that."


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