(Marvin Joseph/The Washington Post)

The violence has been relentless during this city’s Summer of Freddie Gray.

Three months after parts of this city burned in anguish over the death of Gray, who was fatally injured while in police custody, the carnage has continued. In fact, it’s accelerated.

With 11 people shot over the weekend — two fatally — the city closed out July with a record-tying 45 murders. To put that in perspective, the similarly sized District registered 16 murders last month.

“I’ve never seen anything like it,” said Johnnie Harris, 65, a retired geological engineer who sat on his stoop in the battered West Baltimore neighborhood of Sandtown-Winchester. He was facing a makeshift memorial of faded, stuffed animals to someone who’d been killed.

“That one’s old, happened about a year ago,” he said. “New ones are up everywhere else, though.”

A blighted home in West Baltimore carries graffiti pleading for change. (Patrick Semansky/Associated Press)

Indeed, a tour through bleak Sandtown, where Freddie Gray was arrested and cars and buildings burned after his funeral, shows little sign of hope or improvement. Every few blocks, there is a burst of color and sparkle — a bunch of Mylar balloons tied to a street sign in honor of a victim of the violence.

The last time this much blood was shed on Baltimore’s streets was August 1972 — in the summer of the Olympic massacre in Munich, the summer New York had 57 killings in 24 hours, the summer when the “Bloody Friday” bombings left nine people dead in Belfast.

Ancient history, right?

In those 43 years, the Olympics have had only one other deadly attack, New York City is practically Disneyland (maybe even cheaper) and the Troubles of Northern Ireland have largely been quelled.

But Baltimore, poor Baltimore, is actually worse off than it was in 1972. Back then, the city’s population was vastly larger, with 900,000 residents.

Now its population has shrunk to about 623,000, and parts of the city are so blighted that it’s hard to tell which buildings were destroyed during the rioting this spring and which buildings have been rotting for decades.

Police officers head back to buses in April after patrolling the intersection of North and Pennsylvania avenues, the scene of rioting. (Jabin Botsford/The Washington Post)

Baltimore isn’t the only American city suffering through a violent summer. The District is also experiencing a surge in shootings this year. We’ve had a 20 percent jump in homicides, and people are beginning to freak out. The body count has also gone up in New York, New Orleans, San Antonio, St. Louis, Chicago, Dallas and Milwaukee.

The police chiefs from big cities across the country met in Washington on Monday to discuss what’s clearly a nationwide trend.

For 20 years, we saw crime plummet. The country’s homicide rate is now half of what it was in the 1990s.

Experts have tried to figure out why homicides and other crimes dropped, attributing the decrease to zero-tolerance laws, the war on drugs, three strikes laws, job growth, prison growth, the economy and better emergency room medicine.

But whatever juju we had is fading. And for the first time in two decades, we’re seeing a collective rise in bloodshed. Chicago homicides? Up 17 percent over last year. Atlanta? A 32 percent increase. New York? Murder is up by 13 percent.

“We have come too far to lose traction now,” declared D.C. Police Chief Cathy Lanier, as she discussed the trend last week.

Baltimore’s struggles are particularly acute. The city is still reeling from the fallout of Gray’s death. The 25-year-old died after he suffered a spinal injury in police custody in April. Six police officers have been charged in his death. The unrest that rocked the city and the spike in violence just cost Police Commissioner Anthony Batts his job.

He’s been replaced by interim chief Kevin Davis, who pointed out that other cities are grappling with more murders, while acknowledging that Baltimore’s problem is worse.

“Certainly, it’s pronounced here in Baltimore,” he said in a news conference Sunday.

“But I believe the circumstances contributing to our uptick are probably not unlike the circumstances contributing to the uptick in homicides in other jurisdictions across our country,” Davis said.

Is Baltimore simply the leader in a nationwide backslide?

Some blame the increase in violence on the “Ferguson Effect” — officers pulling back on tough enforcement because of the intense focus on police-involved shootings like the one that killed Michael Brown in Ferguson, Mo., last August.

In neighborhoods where police have long been viewed with suspicion, people use their cellphones like all-seeing periscopes every time police officers get out of their cars. Officers and the unions that represent them describe a combination of surveillance and skepticism, with body cameras, ACLU recording apps and jeering wherever they go.

Harris, the stoop sitter who has lived in Sandtown for 36 years, said the police presence in his neighborhood has evaporated since the riots.

“It’s legal murder,” he told me. “Police aren’t doing anything. They stopped working. And they’re just letting everyone kill each other, and they look away.”

It’s not that simple, though.

Because minutes before I talked to Harris, I happened upon Shawn Chester, his hands in the air, a Baltimore police officer in body armor turning his shorts pockets inside-out.

Chester, 37, told me that he was trying to get a cab to go pick up his 3-year-old daughter when the officer stopped and searched him.

“He thought I was selling drugs,” Chester said, putting himself back together. “He didn’t find anything on me. He apologized to me.”

That didn’t look like the blue flu to me.

And there’s hardly any sign that the police are being less aggressive nationally. On-duty police officers shot and killed more people in July than during any other month this year. At least 103 people died by police gunfire last month, according to The Washington Post’s database tracking fatal police shootings.

Baltimore’s surge in violence isn’t easy to explain. But here and everywhere, we’ve got to find a way to stop the bleeding.