By day, 38th and Chicago has become a pilgrimage site for those seeking to protest the police killing of George Floyd and other racial injustices.

But when the sun goes down, locals say, it's a different story, with gunfire ringing through the night and police sometimes nowhere to be found.

Questions surfaced. Where are the guns coming from? How did they end up in the hands of gang members who cruise the neighborhood after dark?

A case making its way through federal court might help provide some answers. The defendant, David C. Jensen, was previously indicted on charges of lying about smoking marijuana on his application to buy a gun, but new court filings show authorities suspect him of selling guns out of the trunk of his car, just as gun violence began to escalate near the Floyd memorial site.

Authorities were first tipped off to Jensen's alleged scheme on July 9 when a business owner near 38th and Chicago reported that a man had walked into his store looking to sell a box of 40-50 firearms, according to an affidavit for a search warrant. The owner told authorities that the neighborhood had effectively been taken over by gang members, who openly toted guns and set up roadblocks, deciding who should be allowed to come and go.

Investigators began canvassing local gun stores and learned that between 2013 and 2015, Jensen, now 32, had legally purchased about 50 firearms — many of them "tactical" style rifles — from Frontiersman Sports in St. Louis Park and another 11 guns from Bill's Gun Shop in Robbinsdale, according to the affidavit. Jensen, however, was banned from Frontiersman last year after he repeatedly tried to purchase firearms from customers who had come to the store to sell their guns, authorities said. Ballistics tests showed that at least two of the guns that he bought later showed up at crime scenes.

When investigators started surveillance of the Floyd memorial site, officers and ATF agents spotted Jensen in the area, driving past the barricades "used by gang members to vet who enters the area so as to allow them to conduct illicit business undisturbed," according to the affidavit.

After he left, investigators tailed Jensen to a clinic in Wayzata and later obtained a search warrant for his vehicle, which turned up five guns, loaded magazines, ammunition, body armor and drug paraphernalia, the filings say. Another 11 guns were reportedly seized during a raid of his Brooklyn Park home.

A forensic analysis of his phone revealed at least 39 text threads dating back to early 2019 related to the purchase or sale of firearms, prosecutors say. It also showed evidence that Jensen worked for a time as a firearms permit instructor at Twin Cities Carry. In some texts, Jensen reportedly bragged to others that he had "hung out with the gang bangers" near the Floyd memorial. In others, he sent photos of himself holding a gun and apparently guarding the makeshift barricades that dot the site.

Jensen, through his attorney, Bruce Nestor, has filed a motion to quash the warrant by arguing that authorities lacked probable cause to search his vehicle. When reached by telephone on Wednesday, Nestor declined to comment on the case. Jensen, who has no prior criminal history, has not been charged in connection with gun dealing.

Prosecutors conceded in response to Nestor's motion that "the situation at the George Floyd memorial has been complex and emotional, and has involved individuals with a wide array of purposes," but argued that the evidence against Jensen suggests darker motives for his visits to the site.

"Officers had various pieces of information suggesting that Jensen was far more than a law abiding gun hobbyist or a peaceful community activist — including a high volume of firearm purchases attributed to Jensen, and various indicia that he had an inventory of guns he was selling (and/or offering to sell) out of his vehicle, in a volatile area experiencing a spike in crime," assistant U.S. attorney Ruth Shnider wrote in the filing. "The fact that a local gun shop (certainly no critic of the Second Amendment) had felt it necessary to ban Jensen from their premises for trying to purchase guns directly from customers was also strongly indicative of profit-motivated 'dealing' behavior."

The area around 38th and Chicago had long held a reputation as a hangout for gang members, but after May 25, the intersection was transformed into a sacred space for people seeking to memorialize Floyd and to heal.

Still, nighttime has brought regular gunfire, residents and authorities say. In the seven weeks after Floyd's death, there were 11 people shot and 233 ShotSpotter activations in the two-block radius around the intersection, authorities said. The area didn't have a single ShotSpotter activation during the same period last year.

Then, on July 5, police say Leneesha Columbus, who was pregnant, was fatally shot by her on-again, off-again boyfriend, who then allegedly turned his gun on a man working security nearby who tried to intervene. The baby girl was delivered but was taken off life support a month later.

In the immediate aftermath of Floyd's death, officers responding to emergencies near the square said they were frequently met with hostile crowds, and even recently, police can be heard on scanner traffic saying that they wouldn't respond to reports of gunfire in the area unless there was a victim, feeding into the perception that it was a "no-go zone" — an area where police are reluctant to respond.

Alexandra Cooper, who lives nearby, said that Floyd's death and the subsequent rise in crime has left many of her neighbors feeling conflicted: on the one hand, they are more careful about calling law enforcement into their community.

But now, "we're talking about imminent threats to people's lives," she said.

Minneapolis police Lt. Matthew St. George said that despite the civil unrest and "historic" crime surge that followed Floyd's death, police are still doing their jobs. To prove his point, he cited recent crime statistics showing that police have recovered 945 guns from the streets, already eclipsing the 940 firearms seized all of last year. "We have a lot of officers who have left the job. We are in a place where the officers are working hard, they're doing more work than they did last year at this time, and even with all that they're continuing to do a good job and do their work, and taking guns away from bad people," said St. George, who runs the department's Assault Unit.

T.J. Valtierra said he attended several community meetings where neighbors expressed frustration with the rising crime and with outsiders who claimed to speak on behalf of their community.

"I can't say when it started, but it was shortly after [Floyd's death], we went months and months where we heard gunshots probably literally every night," said Valtierra, a youth worker and pastor who lived at 37th and Elliot until a few months ago, when he moved his family to the North Side to escape the violence.

Rashane Bryant, who runs a youth mentor program called Becoming a Man, said he thinks some of the violence stems from criminals taking advantage of the lack of police presence in the area.

Many of the gang members hanging around are not only in need of jobs, but also services addressing "mental and physical [health], self-esteem and all that." But, he said, he draws the line at people bringing guns into a community in pain.

"Yes, there are responsible people who have guns, but I can't tolerate bringing guns into our community and selling them to our people," he said. "A lot of the people that you're selling to, they're lost, and so they're not going to know what to do with them."

Libor Jany • 612-673-4064 • Twitter: @StribJany