'Insanity': 4th of July mass shootings leave 20 dead, 126 injured

Amid celebrations and fireworks over the long Fourth of July holiday weekend, cities across America were left reeling from the scourge of gun violence as mass shootings occurred at block parties and other festive gatherings.

Twenty people were killed and 126 were injured in 22 mass shootings that erupted across the country between 5 p.m. ET Friday and 5 a.m. ET Wednesday, according to the Gun Violence Archive, a website that tracks shootings nationwide. The website, which defines a mass shooting as a single event with four or more victims either injured or killed, reported that the holiday mass shootings happened in 17 states and Washington D.C.

Among the major cities rocked by mass shooters were Baltimore, Philadelphia, Boston, Chicago and Fort Worth, Texas.

The shooting victims included a 15-year-old boy, and many children were among the wounded.

"This is a societal problem that we're dealing with, a mass shooting where a disagreement turns into 28 people shot. This is insanity," an emotional Bill Ferguson, president of the Maryland State Senate, said following a mass shooting that occurred at a Baltimore block party on Sunday. "This cannot be the society that we are expected to live in. We have to do better."

John Cohen, a former U.S. Department of Homeland Security acting undersecretary for intelligence, said the holiday shootings highlighted the challenges law enforcement officials face with more and more people carrying firearms and using them to settle disputes regardless of innocent people getting caught in the crossfire.

"While typically we look at mass shootings from the perspective of whether it was ideologically motivated or motivated by some perceived grievance fueled by underlying behavioral health challenges, what we have also seen in this current threat environment is an increase of mass casualty violence as a reaction to disputes or disagreements with others," Cohen, an ABC News contributor, said.

Cohen said it appears that both types of shooters were involved in the holiday mayhem.

"It's hot, people are angry, there is a return to people attending crowded public events and more people believe it is justified to use violence in response to a dispute," Cohen said. "So, when a dispute or argument escalates into violence -- instead of a fist fight -- they are seeing mass casualty shootings."

Philly shooting leaves 5 dead, children injured

One of the deadliest shootings unfolded over the holiday weekend in Philadelphia, when a man armed with an AR-15 style rifle, a pistol, extra magazines and wearing a bulletproof vest and a ski mask, allegedly went on a rampage, seemingly firing at least 50 shots randomly at victims, according to police.

Five people, including a 15-year-old boy, were killed in the massacre that broke out around 8:30 p.m. ET Monday in the Kingsessing neighborhood of Philadelphia, police said. Surveillance video obtained by Philadelphia ABC station WPVI appeared to show the gunman shooting at vehicles at a nearby intersection. A 33-year-old mother and one of her 2-year-old twins were injured by glass, as her other twin was suffering from four gunshot wounds to the legs.

Police said a 13-year-old child was also wounded in the incident.

The suspect, 40-year-old Kimbrady Carriker of Philadelphia, was arrested and appeared in court Wednesday for an arraignment on charges of murder and attempted murder, as well as aggravated assault, reckless endangerment, carrying a firearm without a license and other charges. Carriker is being held without bail, and a preliminary hearing has been scheduled for July 24.

Police identified those killed in the incident as Lashyd Merritt, 20; Dymir Stanton, 29; Ralph Moralis, 59; Daujan Brown, 15; and Joseph Wamah, Jr., 31.

"This country needs to examine its conscience and find out how to get guns out of dangerous people's hands," Philadelphia Mayor Jim Kenney said. "A person walking down the street with an AR-style rifle and shooting randomly at people while wearing a bulletproof vest with multiple magazines is disgraceful, but an all too common situation in America."

9 shot in nation's capital

The string of mass shootings included one in the nation's capital, where at least nine people were wounded early Wednesday in a drive-by shooting, according to police.

The shooting unfolded just before 1 a.m. ET on Meade Street in the northeastern part of the city. Assistant Chief Leslie Parsons of the Washington D.C. Metropolitan Police Department told ABC News a dark-colored SUV was driving through the area when someone inside the vehicle began firing in the "direction of some of our residents that were outside, just celebrating the Fourth of July."

No arrests were immediately announced.

1 killed, 5 shot at Chicago Independence Day gathering

A man was killed and five other people were wounded when gunfire broke out at a Fourth of July gathering in Chicago early Wednesday, police said.

A group of people were standing outside a residence in the city's Englewood neighborhood when a gunman opened fire on them at about 4:47 a.m., according to a police incident report. A 35-year-old man was shot in the chest and pronounced dead at the University of Chicago Medical Center, police said.

A 20-year-old man, who was shot in the head and severely beaten during the incident, was critical condition at Stroger Hospital, according to police. A woman and three men were also hospitalized with gunshot wounds, police said.

No arrests were announced and police said the circumstances of the incident were under investigation.

Five wounded in Boston

At least five people were shot and wounded in Boston early Wednesday when at least one gunman opened fire on a group of people who were apparently setting off fireworks, police said.

The shooting unfolded around 2 a.m. ET in the Mattapan neighborhood of Boston, police said. All of the victims were hospitalized with non-life-threatening injuries, according to police.

Boston police said the crime scene was blocks long.

Two men and a woman were arrested on charges related to the shooting, according to police. The names of the suspects were not immediately released.

Baltimore block party shooting kills 2, injures 28

Multiple shooters are believed to have opened fire at a large block party in Baltimore early Sunday, killing two people and injuring 28 others, police said.

The mass shooting unfolded around 12:30 a.m. ET in the Brooklyn Homes neighborhood in the southern district of the city. Baltimore Acting Police Commissioner Richard Worley said officers rushed to the scene when numerous 911 callers reported shots being fired.

Killed in the shooting were 18-year-old Aaliyah Gonzales and 20-year-old Kylis Fagbemi, according to police.

Among those wounded by gunfire were 15 victims between the ages of 13 and 17, Worley said.

Based on different caliber shell casings collected at the scene, investigators believe multiple people fired weapons, officials said.

No arrests have been announced. A $28,000 reward is being offered for information leading to the arrest and prosecution of the assailants.

11 shot, 4 fatally, at Louisiana block party

An annual block party in Shreveport, Louisiana, turned deadly late Tuesday when a number of armed people unleashed a barrage of gunfire at an annual Fourth of July block party, police said.

Shreveport Councilwoman Tabatha Taylor said the shooting occurred just before midnight Tuesday at a holiday block party and birthday event. Taylor said the shooter or shooters showed up at the party and opened fire without warning.

The names of those killed were not immediately released.

No arrests have been announced.

4 shot in Lansing, Michigan

At least four people were shot on a street in Lansing, Michigan, early Wednesday, according to police.

The shooting occurred in the South Washington Square neighborhood near downtown Lansing, according to police. The victims all suffered non-life-threatening injuries.

Police released few details about the shooting.

No arrests were announced.

Child among those wounded in Fort Worth shooting

At least three people were killed and eight others were injured, including a child, in a shooting that broke out in a parking lot late Monday in Fort Worth, Texas, police said.

The Fort Worth police officers responded around 11:40 p.m. CT Monday to reports of gunfire in the Como section of Fort Worth, where hours earlier the ComoFest, an annual Fourth of July celebration, had wrapped up, police said. Upon arrival, the officers found multiple gunshot victims in a parking lot, according to police.

Fort Worth Mayor Mattie Parker called the shooting "heartbreaking" for the city and, particularly, the neighborhood it occurred in.

"This community has worked so hard not just to put on wonderful festivities to celebrate Independence Day, but this is also about their community," Parker said.

Police said a child was among those wounded in the shooting.

The shooting broke out when several men showed up and "started firing into the crowd indiscriminately," police said in a statement.

No arrests were announced.

10 injured in Kansas nightclub shooting

Eight people were shot and two were trampled when a gunfight involving multiple patrons erupted early Sunday inside a Wichita, Kansas, nightclub, sparking a chaotic stampede for the exit door, according to police.

At least four guns were fired during the wild shootout that erupted at 12:58 a.m. CT Sunday inside the City Nightz nightclub in the Old Town section of Wichita, Lt. Aaron Moses, executive officer of the Wichita Police Department, said at a news conference. One of the alleged gunmen was taken into custody and investigators are working to identify others.

On Monday, police identified the suspected gunman as 31-year-old Brandon Young of Florissant, Missouri. Young was arrested on two counts of aggravated battery stemming from the nightclub shooting, police said.

Police expect more arrests to be made.

Wichita Police Chief Joe Sullivan announced Monday that the nightclub where the shooting occurred has been suspended from doing business for 30 days. During a news conference, Sullivan said the shooting would have likely been avoided had the nightclub screened patrons entering the business.

Officers have responded to 12 incidents associated with City Nightz in the past year, including investigating aggravated battery cases and a May 21 drive-by shooting, according to Detective Chris Merceau of the Wichita Police Department.

"We need to take a strong stance in response to what occurred because, in my estimate, I believe it was totally preventable," Sullivan said of the nightclub's suspension.