Policing such events is a delicate balance for law enforcement, who must weigh the right of revelers to gather with the threat of violence that looms in public and private spaces in a nation awash with guns.

“In many ways, their hands are tied because these types of events are often on private property and people may not do anything to violate the law until someone brandishes a firearm and starts shooting,” said Tom Nolan, who was a Boston police officer for nearly three decades. “So can the police do anything to prevent that? I just think it’s an extraordinary challenge for them to be all places at all times and anticipate things that none of us are expecting.”

Violence often surges in the summer months, when teens are out of school and there are more social events that can quickly turn deadly as tempers flare.

Curfews for young people and increased police presence on the streets are among the strategies cities have historically used to try to combat summer violence.

Police can prepare for parades and other large annual events by monitoring social media chatter ahead of time, requiring a law-enforcement presence for permitted events and changing up their coverage plans depending on how many people are expected when. Ideally, police work with communities who want the protection.

But it’s impossible for law enforcement to monitor every block party or holiday gathering. Vacations can also lead to police departments being thinly staffed over holiday weekends and during summer months, which means calls for loud music and other disturbances can get backed up while police deal with more pressing matters, Nolan said.

“During the time when their services are most in demand, they are stretched far more thinly than they would like to publicly admit,” said Nolan, who was a shift commander in the patrol division.

The gun violence that flared this week in Washington, D.C, Louisiana, Florida, Philadelphia, Texas and Baltimore left more than a dozen dead and almost 60 wounded — including children as young as 2 years old.

See: Gunman wearing bulletproof vest kills 5 in Philadelphia before being arrested

The wave of killings came as the upscale Chicago suburb of Highland Park was marking the anniversary of last year’s mass shooting at a Fourth of July parade that left seven people dead. Security was tight at events aimed at honoring those killed, and the day was capped by a drone show instead of fireworks to avoid the noise that could sound like gunfire.

White House Press Secretary Karine Jean-Pierre condemned the gun violence Wednesday, urging Congress to pass a ban on so-called assault weapons and placing blame on the proliferation of guns in the U.S. “Lives are at stake here, folks. Lives are at stake in communities, the lives of our kids,” she said.

In Baltimore, police knew about the block party at the Brooklyn Homes last year and sent squads to the area to monitor for any potential violence, police said. There wasn’t any.

This year, police officials didn’t discover Sunday’s event was happening until the day of. It wasn’t advertised on social media and no one in the community told officers, so law enforcement officials weren’t properly prepared when violence broke out, interim Baltimore Police Commissioner Richard Worley told reporters. He said police are looking at whether they could have done anything better to make sure something like that doesn’t happen again.

“These are events that are about celebration, about coming together, that are intergenerational and should be sacred to our communities. When a few decide to go and literally create a mass shooting, it’s completely unacceptable,” said Baltimore City Council President Nick Mosby, urging members of the public to work with police to find those responsible.

The 28 injured in Baltimore ranged in age from 13 to 32, with more than half of them younger than 18, officials said. Folding tables and plastic cups were scattered on the street, apparently left behind when people ran from the gunshots.

And police can do everything right but still won’t be able to find every gunman who wants to do harm.

The annual celebration in Shreveport, La., where a gunman opened fire late Tuesday had gone on for a decade with no trouble. Shreveport police said that officers who arrived on the scene had a hard time reaching victims because of the volume of parked cars.

“Now we are the victim of a mass shooting in our community simply because individuals decided to come in and disrupt a good time that individuals were having,” Tabatha Taylor, a Shreveport City Council member said. “A family event that has gone on for years in our community has been disrupted by gunfire because somebody decided to pull their guns and do this. Why? Why?”

The Tuesday shooting along the causeway that crosses Tampa Bay, which killed a 7-year-old, stemmed from an argument over Jet Skis that one group said were coming too close to children playing in the water. The night before, three people were killed and eight others were injured when several men fired indiscriminately into a crowd of hundreds that had gathered in a Texas neighborhood after a festival in the area.

In New York City, the annual J’ouvert and West Indian Day Parade celebrations had been marred by violence for years. Police had to rethink how they approached the event and how they worked with the Brooklyn community ahead of time.

“We all know it. We know the ritual. Pick up the paper the day after and you look at the number of homicides, how many shootings took place? What happened at the parade?” Mayor Eric Adams said last year as he took a victory lap following a peaceful Labor Day weekend. “It didn’t happen this weekend. It did not happen. Why? Because, four days out, we brought together our commissioners, and we said we are going to be a team.”