A man who was wounded in a mass shooting on New Year's Day in Montenegro has died, bringing the death toll to 13

A 14-year-old student has been arrested after bringing a gun to Apalachee High School, the same Georgia high school where a September shooting killed two teachers and two students and wounded others

A top-level meeting in Montenegro is looking for ways to curb illegal weapons after a gunman fatally shot 12 people in a second such tragedy in less than three years in the small Balkan country

A 40-year-old mother was one of six people shot in a New York City convenience store when she was used as a shield by a suspected target, authorities said.

Ten people were shot after several men opened fire at a group of people waiting outside of a music venue in Queens, New York, the NYPD said.

At least 10 people were killed in a shooting in Montenegro, including 2 children, the interior minister says

Four family members, including three Americans, were shot in an attack in Durango, Mexico, that left three of the four dead, officials said.

Jennifer Crumbley, the mother of Michigan high school shooter Ethan Crumbley, is asking to be released from prison on bond pending her appeal outcome.

A Christmas night shooting and stabbing at Phoenix Sky Harbor International Airport resulted in three people shot and one stabbed, police said.

Authorities say the incident took place at a restaurant outside of security checkpoints at Phoenix Sky Harbor International Airport's Terminal 4.

Two people were killed and another six injured in the shooting at Abundant Life Christian School in Madison, Wisconsin, police said.

Police are investigating the online footprint of the 15-year-old girl who allegedly opened fire at her Madison, Wisconsin, Christian school.

Gunfire erupted in Towson, Maryland, on Tuesday evening, leaving 1 person dead and 9 others wounded, according to police.

Wisconsin has a number of firearm-related laws in effect that limit access to children and individuals with a history of violence.

Gunfire erupted in Towson, Maryland, on Tuesday evening, leaving 1 person dead and 9 others wounded, according to police.

A 15-year-old girl allegedly opened fire with a handgun at Abundant Life Christian School in Madison, Wisconsin, killing a teacher and a fellow student.

The shooting happened inside a classroom at Abundant Life Christian School during a study hall of students from multiple grades, police said.

Investigators said 15-year-old suspect Natalie "Samantha" Rupnow fatally shot a fellow student and a teacher before taking her own life at the Madison, Wisconsin, school on Monday.

ABC News’ Linsey Davis speaks with former FBI special agent and profiler Mary Ellen O'Toole about what we know about the teenage girl accused of the shooting at a school in Madison, Wisconsin.

Rep. Mark Pocan says his community is experiencing tragedy because Americans are "addicted to guns."

The shooter was a 15-year-old student, officials said on Monday. Natalie Rupnow, who went by Samantha, died of an apparent self-inflicted gunshot wound.

A teacher and teenage student were killed and six others hurt in a shooting at Abundant Life Christian School in Madison, Wisconsin, on Monday, police said.

The teenage girl alleged to have shot seven victims, two fatally, in an attack on Monday at a Wisconsin school marks the rare occurrence of a female school shooter.

Former FBI and profiler Ellen O’Toole discusses the 15-year-old girl suspect that allegedly shot seven victims, two fatally, in an attack on Monday at a Wisconsin Christian school.

A 15-year-old student killed a teacher and another student in a shooting at the Abundant Life Christian School in Madison, Wisconsin, on Monday, police said.

A man was inside the apartment and was arrested and charged with cruelty to children, police said.

Authorities in Wisconsin are working to figure out what led a 15-year-old student to open fire at Abundant Life Christian School, killing a teacher and fellow student in study hall.

A teenage student and teacher were killed at the Madison, Wisconsin, school on Monday, according to police. Sources say the suspect was a female student at school and is also dead.

The suspect in Monday’s deadly school shooting in Madison, Wisconsin, was a female teenager, multiple law enforcement sources told ABC News.

David Hogg, gun control activist, March for our Lives co-founder and Parkland school shooting survivor reacted to the Abundant Life Christian School shooting in Madison, Wisconsin.

A teacher and teenage student were killed and six students were hurt in a shooting at Abundant Life Christian School in Madison, Wisconsin, on Monday, police said.

Police in Madison, Wisconsin, said they're investigating a shooting at Abundant Life Christian School. Multiple injuries have been reported, police said.

John Diaz De Leon discussed what he saw as an eyewitness to the Abundant Life Christian School shooting Monday in Madison, Wisconsin.

Two teenagers were killed and three other people were injured when gunfire erupted inside a crowded Houston "pop-up party," according to police.

Two teenagers were killed and three other people were injured Saturday night when gunfire erupted inside a Houston "pop-up party."

One person was shot and killed in an "isolated" shooting in on-post housing at Fort Eisenhower on Saturday, according to the base.

The firearm found on the suspect in the murder of the UnitedHealthcare CEO is believed to have been an untraceable ghost gun, according to police.

Police in Pennsylvania are searching for the gunman wanted for killing a young man and wounding his mother during a home invasion in an upscale Philadelphia suburb.

A police officer was fatally shot Sunday night while conducting a traffic stop in Terrell, Texas, police said.

A mother is in critical condition and her son has been killed in a home invasion shooting in a Philadelphia suburb. The suspect is at large and has not been identified, officials said.

Investigators provided more information on the shooting at a Christian school in California that has left two kindergarteners in critical but stable condition.

One person has been killed and three others injured, including the suspected gunman, in a shooting inside an Indiana laundromat, police said.

A gunman opened fire at a Christian grammar school in California on Wednesday, authorities said.

A gunman opened fire at a Christian grammar school in California on Wednesday, authorities said.

UnitedHealthcare CEO Brian Thompson was shot near a Midtown Manhattan hotel in a potentially targeted shooting early Wednesday, according to police.

The suspect took his own life after firing on children at the elementary school in Palermo, California, on Wednesday, the sheriff said. One of the two injured students was airlifted to the hospital.

The shooting of UnitedHealthcare CEO Brian Thompson appears to be a "brazen, targeted attack," police said.

The masked gunman appeared to be lying in wait and shot Brian Thompson several times from behind, the NYPD commissioner said at a news conference.

The shooting, which appeared to be accidental, unfolded Monday in a parking lot in Rancho Cucamonga, the San Bernardino County Sheriff's Department said.

Brian Thompson was shot and killed outside a Midtown Manhattan hotel Wednesday morning. The alleged killer is on the loose and police believe it may have been a targeted shooting.