Dozens of people were killed and hundreds more injured in shootings across the nation over the weekend, and experts warn gun violence could increase as summer officially gets underway on Thursday.

Since Friday, at least 73 people were killed and 308 were injured in shootings including several incidents at outdoor spaces and gatherings like a Juneteenth celebration in Texas, a splash pad in Michigan, a park in Illinois, and a party in Massachusetts, according to the most recent data from the Gun Violence Archive.

Mark Bryant, the archive's executive director, said that although there have been fewer shootings in 2024 than at the same point last year, the country typically sees an uptick in gun violence as temperatures rise and people gather outside for activities during the summer.

"We've been having some very quiet weekends," Bryant said. "So this weekend, which seems like it popped, was actually back up to normal for summertime."

6 hurt including 15-year-old shot in neck in Chicago shooting

Police said six people were injured, including a 15-year-old girl who was shot in the neck, during an early Monday morning shooting at a park in Chicago. In addition to the teen, four adults were shot and another suffered a broken ankle.

Officers responded to a shooting in West Humboldt Park on the city's Northwest Side around 12:45 a.m., Chicago Police Department spokesperson Peggy Benz told USA TODAY. Benz said the suspect remained at large as of Monday morning.

Eight injured at 'pop-up' party in Methuen, Massachusetts

Eight people were injured during a shooting at a "pop-up" party attended by hundreds of people in Massachusetts early Sunday, officials said.

Police responded to 911 calls at 1:55 a.m. Sunday morning for a shooting in Methuen, a city about 30 minutes north of Boston. Upon arrival, police found seven victims with gunshot wounds and an eighth person who suffered serious head injuries, Methuen Police Chief Scott McNamara and Essex County District Attorney Paul Tucker said.

Victims ranged from ages 17 to 23 years old. Police have not arrested anyone involved in the shooting and have asked for help identifying the shooters.

Two killed, 14 injured at Juneteenth celebration in Round Rock, Texas

Police said two people were killed and 14 people were injured during a shooting at a Juneteenth celebration at a park in Round Rock, Texas on Saturday. Gunshots broke out between two groups; 33-year-old Lyndsey Vicknair and 54-year-old Ara Duke, who were not involved in the fight, were killed, the Round Rock Police Department said in a statement on social media Monday.

Police asked the public to share photos or video evidence of the incident. The Bureau of Alcohol, Tobacco, Firearms and Explosives offered a $5,000 reward for information leading to the arrest of the suspect or suspects involved.

"Our hearts are heavy as we mourn the tragic loss of innocent lives and the injuries sustained by several others in Saturday's senseless act of violence," Chief Allen Banks. "Our deepest condolences go out to the families affected by this tragedy."

Michigan splash pad shooting leaves 9 injured, including children

On Saturday evening, nine people were injured during a shooting at the Brooklands Plaza Splash Pad outside Detroit, according to Oakland County Sheriff Michael Bouchard. He said victims included a mother and two children, a husband and wife and a 78-year-old man.

Bouchard identified the suspect as as Michael William Nash, 42, who died by suicide after being "contained" at a home in nearby Shelby Township for several hours following the attack. 

"I love my community, and my heart breaks today," said Bryan Barnett, mayor of Rochester Hills. "When I got on scene I started to cry. Because I know what a splash pad is supposed to be. It's supposed to be a place where people gather, where families make memories, where people have fun and enjoy a Saturday afternoon, and it wasn't today. And as you heard, the victims, families, husbands and wives, what normally happens in our city didn't happen today."

6 hurt, 1 dead in weekend shootings in Indiana

Four separate shooting incidents in South Bend, Indiana over the weekend left six people injured, a high school student dead and a Georgia resident facing possible road rage-related charges, according to the South Bend Tribune, part of the USA TODAY Network. Four male gunshot victims were treated at a local hospital after an officer witnessed gunfire at a Marathon gas station around 4 a.m. early Sunday.

The series of incidents came as the city had been experiencing some of its lowest shooting numbers in many years.

"We can never become comfortable with decreasing gun violence stats until our shooting numbers are zero," South Bend Police Department Chief Scott Ruszkowski said.

Gun violence appears to be decreasing

Despite the violent incidents over the weekend, Bryant said his data shows there has been a marked decrease in gun violence following the record highs seen in 2020 and 2021, though some forms including mass killings and murder-suicides have risen. The most recent data from the Centers for Disease Control and Prevention shows gun homicides declined in 2022 though gun suicides reached an all-time high and the gun suicide rate among Black teens surpassed that of their white peers for the first time.

In 2024, there have been more than 7,700 people killed and more than 14,600 people injured by guns, according to the Gun Violence Archive. Bryant believes the overall decline is likely to continue through the second half of the year.

"Overall, we're doing better," he said.

According the mass killings database run by USA TODAY, The Associated Press and Northeastern University, 2023 saw the second most mass killings in a single year since tracking began in 2006, the most mass shootings and the most public mass shootings.

By this point last year, the country had already had six mass killings - defined as an attack in which four or more people are killed - in public places, according to James Alan Fox, a professor of criminology, law and public policy at Northeastern University in Boston who oversees the database. So far this year, there have been none, Fox said.

"This is obviously a terrible weekend, but in the larger context, things are actually better than they have been," he said.

Does violence increase in the summer?

Gun violence experts warned violent crime tends to increase during the summer as Americans gather in large crowds for concerts, parades, and other outdoor activities.

"There's definitely a relationship between temperature and violence and that probably has to do with just more people, more interactions, more firearms, more alcohol and things of those nature," said Joshua Horwitz, co-director of Johns Hopkins Center for Gun Violence Solutions. "It's just unfortunately in this day and age, simple arguments - when you're armed - turn lethal."

Bryant said he's also concerned there may be an increase in political violence as tensions rise over the presidential election in November. But Fox says the decrease in public mass killings is a positive sign.

"There may be increase this summer, but it's not going to wash out the downturn we've seen in the first half year," Fox said.

What can the US do about gun violence?

Horwitz said the spike in gun violence after 2020 may have been due to an increase in gun sales, social dislocation brought on by the COVID-19 pandemic and the distrust between community and law enforcement following the murder of George Floyd creating the "perfect storm for gun violence.

He said though it's difficult to draw conclusions until more data from the CDC is released, some of the recent reduction in gun violence may be due to the work of community violence interruption programs and funding from legislation like the Bipartisan Safer Communities Act.

Horwitz pointed to a number of strategies to further reduce gun violence including red flag laws, waiting periods, background checks, secure firearm storage and limiting the places guns can be carried in public as well as continued investment in violence intervention programs.

"What you're looking for is people who are really at the highest risk of violence," he said. "Can we spend our resources trying to make sure that they won't pull the trigger?"

Contributing: Jennifer Dixon, Detroit Free Press; Julia Gomez, Natalie Neysa Alund and Grace Hauck, USA TODAY