On a Sunday afternoon nearly four years ago, Elvin Daniel was in his garden when he got a call from police: His sister, Zina Haughton, had been shot at work.

Zina’s abusive husband, Radcliffe Haughton, used a semiautomatic handgun that he bought from a man in the parking lot of a fast-food restaurant in Germantown the day before the shooting. He killed Zina Haughton, Maelyn Lind and Cary Robuck and wounded four others at the Azana Salon & Spa in the Milwaukee suburb of Brookfield. He then used the weapon to kill himself.

Zina Daniel Haughton, 42, left behind two daughters, ages 20 and 13.

Daniel, who owns a gun, said he was shocked that his late brother-in-law was able to buy a firearm despite a judge’s order prohibiting Radcliffe Haughton from possessing a gun.

“We started to find out that people actually can get guns without a background check,” said Daniel, who lives in Illinois, where all gun purchasers must pass a background check. “As naive as I was back then, I thought because I go through a background check, everybody did. So we start to find out about all these loopholes that we have in our laws.”

Since his sister’s death, Daniel has pushed lawmakers to expand criminal background checks beyond licensed dealers to private sellers, such as those who advertise on Armslist. That is where Haughton found the seller of the gun he used in the mass shooting.

“I mean, the day before that (shooting), I was one of those that says, ‘You know what, leave me and my guns alone,’ ” Daniel said. “I still feel that, but I believe that everybody should go through a background check when they buy a gun to keep guns out of (the hands of) people that shouldn’t have them.”

Coburn Dukehart / Wisconsin Center for Investigative Journalism

Zina Haughton’s daughter, Yasmeen Daniel, was at the salon and saw her mother shot to death. Her stepfather also tried to shoot at her, but Daniel was saved when Lind stepped in front of her.

She is now suing Armslist, charging the website facilitated the illegal gun purchase that led to her mother’s death. Armslist has asked a Milwaukee County Circuit judge to dismiss the lawsuit, arguing that under Wisconsin law, the company cannot be held liable for the actions of people who advertise on its site.

Eighteen states plus the District of Columbia have expanded background checks beyond federal law to include at least some private sales. Two more states — Nevada and Maine — have expanded background checks on the ballot this fall.

Background checks proven, popular

A Marquette Law School Poll this year found 85 percent of registered voters in Wisconsin, including 84 percent who have guns in their homes, say they support closing the private-sale loophole. A CNN poll in June showed 92 percent of respondents nationwide favored expanded background checks.

Officials in Milwaukee are working with community leaders and nonprofit groups on a plan to reduce gun violence. A top recommendation: Expand criminal background checks to private gun sales. (That initiative is partially funded by The Joyce Foundation, which also provides funding for the Wisconsin Center for Investigative Journalism’s coverage of gun violence prevention issues.)

Milwaukee Police Chief Edward Flynn said expanding background checks to private sellers would not cure all of Milwaukee’s violence, but it would be a step.

“Background checks for private party gun sales would add another layer of oversight that may help keep guns out of the hands of those prohibited from possessing guns,” Flynn said in an email.

But Republicans who run Wisconsin state government have blocked attempts to require background checks on purchases from private sellers. That position is shared by the National Rifle Association, the nation’s most powerful gun lobby, which spent $3.6 million to support Republicans and conservative candidates in Wisconsin between 2008 and 2014, according to the Wisconsin Democracy Campaign.

A 1997 study estimated that 40 percent of U.S. guns are obtained outside of federally licensed gun stores. Updated research from Harvard University and Northeastern University includes soon-to-be published findings that roughly one-third of gun acquisitions today occur outside of such licensed dealers.

Everytown for Gun Safety

Expanding background checks to private sales is the “most promising” strategy to prevent gun violence, said Ted Alcorn, research director for Everytown for Gun Safety, the nation’s largest gun violence prevention advocacy organization. The group, which began as Mayors Against Illegal Guns, is bankrolled by Michael Bloomberg, the former New York City mayor and gun-control advocate. Milwaukee Mayor Tom Barrett helped co-found the organization.

Firearm violence includes two elements, Alcorn said: a gun and a person who poses a high risk of causing harm with it. Background checks act as a gatekeeper, he said, preventing individuals at risk of harming others from accessing guns.

University of California Regents

“Criminologists and law enforcement officers say this is … the biggest weakness with the gun laws that we currently have in place because it leaves an open door for prohibited people like convicted felons and domestic abusers to buy firearms without a background check, no questions asked,” Alcorn said.

Dr. Garen Wintemute, director of the Violence Prevention Research Program at the University of California-Davis, has studied various policies for more than 30 years and agrees universal background checks are among the most effective at preventing gun violence.

Daniel Webster, director of the Johns Hopkins Center for Gun Policy and Research, also has studied background checks. Webster and his fellow researchers found that Connecticut saw a 40 percent drop in the firearm homicide rate over a decade after universal background checks were enacted. In contrast, when Missouri repealed such a law in 2007, firearm homicide rates rose 23 percent, Webster has found.

Johns Hopkins Center for Gun Policy and Research

The permit-to-purchase laws implemented in Connecticut and repealed in Missouri require buyers to pass background checks and get a license from a state or local police agency to buy a firearm. Some states require a permit for all firearms and some only for handguns. In some states, permit holders must first go through safety training or an exam.

Another Webster study found levels of illegal gun trafficking were about half in cities where the state required background checks for private handgun sales.

But a University of Pittsburgh study this year discovered that most criminals found ways around laws aimed at keeping guns out of their hands. Researchers traced the origins of 893 firearms recovered by Pittsburgh police in 2008. The study found 79 percent of perpetrators were not the legal owner of the firearm used in the crime — bolstering the gun-rights argument that laws do not stop criminals who want guns. Pennsylvania requires background checks for all handgun purchases.

NRA spokeswoman Catherine Mortensen said these types of laws are tantamount to “criminalization of the private transfer of firearms.”

“These gun control laws criminalize the commonplace practices of law-abiding gun owners,” Mortensen said in a written statement. “By imposing government mandates and fees they cost law-abiding gun owners time, money and freedom.”

Mortensen cited work by economist John Lott, Jr. In his 2016 book, “The War on Guns, Arming Yourself Against Gun Control Lies,” Lott writes that data from all 50 states from 1977 to 2005 shows murders were 49 percent higher and robberies were 75 percent higher in states with expanded background checks.

Lott is founder and president of Crime Prevention Research Center, a Colorado nonprofit that studies the relationship between gun policy and public safety. The center says it receives no funding from the NRA.

Lott’s influential studies have been disputed by some academics for faulty statistical analysis and allegedly fabricated research. And he has acknowledged posing as “Mary Rosh,” a former student, in posts praising his own teaching and research. Lott has likewise criticized Webster’s research, accusing him of cherry-picking in the study of Missouri’s repealed law.

Republicans mum on checks

In emotional testimony before a U.S. Senate committee in 2014, Elvin Daniel described himself as “a Republican, an avid hunter (and) a gun owner” who is “a strong supporter of the Second Amendment, and an NRA member.” Nevertheless, he urged the senators to pass universal background checks and make some “good come out of (Zina’s) death.”

“It is heartbreaking to know that our weak gun laws continue to allow dangerous abusers to buy guns without a background check,” he said.

The argument failed to sway any Republican senators. Two years later, on June 20 after a gunman killed 49 people and wounded 53 others at an Orlando, Florida nightclub, a Senate filibuster and vote resulted in a 56-44 largely party-line vote against expanded background checks. Wisconsin’s Republican Sen. Ron Johnson voted no; Democratic Sen. Tammy Baldwin voted yes.

On June 23, House Democrats staged a sit-in to try to force a vote on a measure to expand background checks and another that would have prohibited people on no-fly lists, including the Orlando shooter, from buying guns. Republican Speaker Paul Ryan of Wisconsin blocked that effort, calling it a “publicity stunt.”

In Wisconsin — where an epidemic of gun violence fueled by illegally obtained firearms is raging in Milwaukee — lawmakers have avoided voting on background checks. Bills introduced by Democrats to expand background checks in recent sessions have died without a hearing.

Republican Gov. Scott Walker has said he opposes expanding background checks. In a written response to questions from the Wisconsin Center for Investigative Journalism, Walker spokesman Tom Evenson said Wisconsin already requires background checks; he did not address the issue of private sales, which require no such scrutiny.

Other top Republicans are mum on why the Legislature has declined to consider expanding background checks.

Assembly Speaker Robin Vos, R-Rochester, did not respond to emails seeking comment.

Email and phone messages sent to Rep. Joel Kleefisch, R-Oconomowoc, chairman of the Assembly Committee on Criminal Justice and Public Safety, also were not returned. He told Wisconsin Public Radio in 2015 that he opposed the Democrats’ bill but gave no explanation.

‘Don’t ask, don’t, tell’ for guns

Wintemute said there are “two systems of gun commerce in the United States”: Sales by licensed retailers that require background checks, paperwork and a permanent record; and transactions between two private individuals requiring no screening or record keeping.

Wintemute has seen the systems in action during his visits to gun shows in Wisconsin and elsewhere. He calls it “Don’t ask, don’t tell” for guns.

“I’ve watched people go up and negotiate the purchase of the gun from a vendor at a gun show, not realizing that they’re talking to a licensed dealer,” Wintemute said. “And just as the negotiation is concluding, out comes the paperwork. And the buyer says, ‘Wait, you’re a dealer?’ And the seller says ‘Yes,’ and the buyer just laughs and walks away and goes and finds a private party to buy from.”

Coburn Dukehart / Wisconsin Center for Investigative Journalism

At the Badger Military Collectible Show at the Waukesha Expo Center Aug. 5, some licensed dealers told a reporter that they have witnessed the same thing. At this show, old military uniforms, medals and vintage firearms were sold next to tables with newer handguns and rifles. Licensed dealers were vocal in their thoughts on expanding background checks to private sales, but several unlicensed sellers declined interview requests.

Marty Brunner, who goes by the nickname “Machine Gun” Marty, is a licensed gun manufacturer and dealer. “NRA4 EVER” is tattooed across the knuckles of both his hands. Brunner believes purchasers go to private dealers because “they have something to hide.” He also believes private vendors are more likely to sell “hot guns” previously used in crimes.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

Tom Hardell, owner of Tom’s Military Arms & Guns, said he “definitely” supports universal background checks. Hardell, who mostly sells handguns, said he has turned down a lot of buyers after running a background check. Many of them, he said, are “gang bangers.”

“It hurts me as a business, and it hurts Milwaukee because that’s where the guns are coming (from),” Hardell said.

Ron Martin, a licensed dealer who travels across Wisconsin selling hunting rifles, said implementing background checks for everyone could “level the playing field” between licensed and unlicensed firearm sellers.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

Martin is not sure expanding background checks would help to reduce firearm violence, however.

“You could put all the laws you want, but the last I checked criminals don’t abide by laws,” Martin said. “They don’t buy guns — they steal them.”

Former gang member: Guns easy to get

But Rico, a former gang member and admitted criminal from Madison, told a reporter that he bought his guns, finding it easy to amass numerous high-powered weapons after he failed a background check by a licensed dealer. While Rico has bought some of his guns “on the street,” he also purchased weapons at gun shows. He asked that his full formal name not to be used because he described committing crimes that could subject him to prosecution.

The 27-year-old estimated that he owns more than 20 guns — all of them bought without passing a background check.

“To be honest, I lost count. I got many. I got assault rifles, I mean, just regular hand pistols, they could be 9-millimeter Berettas, mini-AKs, ARs,” Rico said, listing a variety of semi-automatic weapons. He photographed many of them at the request of a reporter.

He bought several firearms without a background check at a Black River Falls gun show. He used the same terminology as Wintemute to describe private transactions: “Don’t ask, don’t tell.”

It is possible that Rico could qualify to buy a gun after undergoing a background check. He was charged with a felony in 2009 — possession with intent to deliver marijuana — but the case was dropped for lack of evidence. Rico believes he could have fought the background check denial. He chose not to.

“I might as well buy it from a third party where they don’t do background checks, like gun shows, private sales,” Rico said, saying such transactions are similar to “people who’re just selling them … on the street.”

He said universal background checks would not keep criminals from getting guns.

During his years in the gang, Rico said he used guns for intimidation and robbery — even a shootout. Rico acknowledged using firearms to rob people at ATM machines.

“I mean, the more crime you did … the more elite, the more alpha you were,” he explained.

He described one incident in Milwaukee about 10 years ago in which two cars approached his group on the street. Somebody said something in Spanish that provoked his group. At least 15 shots were traded in a matter of moments, he said.

Rico said he has quit the gang life. He went back to school, and now works in an office as a tech specialist. He has turned in his gangster attire for gym gear; he hopes to become a certified trainer.

One remnant of his old lifestyle stayed.

“I kept the firearms,” Rico said.

Lawsuit targets Armslist

For several years before her death, Zina Haughton had been physically abused by her husband. When the violence escalated in October 2012, she got a restraining order and moved out of the couple’s Brown Deer home, testifying that his threats “terrorize my every waking moment.”

The court granted her protection, prohibiting him from approaching Zina Haughton for four years and from possessing firearms, a ban that would have lasted until October 2016.

If Radcliffe Haughton had attempted to buy from a licensed dealer, he would have been blocked by a background check, and police would have been alerted to his attempt to illegally acquire a gun, according to the lawsuit filed by Yasmeen Daniel with help from the Brady Campaign to Prevent Gun Violence.

Instead, he visited Armslist.com.

The lawsuit argued that Haughton’s “extreme urgency, lack of discernment, and preference for a high-capacity magazine” should have alerted Armslist proprietors.

Without any screening or background check, Radcliffe Haughton purchased a FNP-40 semi-automatic handgun for $500 from a private seller in a McDonald’s parking lot.

The complaint argues Armslist proprietors designed the site to exploit the loophole to allow private sellers to cater to prohibited purchasers. It notes that the website has been traced to several incidents in which prohibited purchasers used firearms in Wisconsin and elsewhere.

Websites including eBay, Amazon and Craigslist have banned private gun sales. The complaint argues that Armslist strategically fills the online void left for private gun sales “to enable the sale of firearms to prohibited and otherwise dangerous people.”

The lawsuit also alleges such transactions circumvent other safeguards, including federal restrictions on interstate transfers of guns, state waiting periods and state-specific assault weapon bans.

Armslist attorney Eric Van Schyndle did not respond to several messages seeking comment. Milwaukee County Circuit Judge Glenn Yamahiro has scheduled a Nov. 1 hearing to decide whether to dismiss the case. In 2014, Armslist defeated a similar lawsuit in Illinois.

Background checks stall in Wisconsin

State Sen. Nikiya Harris Dodd, D-Milwaukee, and state Rep. Terese Berceau, D-Madison, co-sponsored a bill again in the most recent legislative session to implement universal background checks. Berceau called it a “common sense” step to reduce gun violence.

Alexandra Arriaga / Wisconsin Center for Investigative Journalism

“It seems really obvious to me that if you are a person who knows that you can’t pass a background check, you’re going to buy from one of these private sellers, and that is indeed what’s going on,” Berceau said.

Under the bill, all firearm transactions would have to go through a licensed dealer, and buyers would have to pass a background check, with certain exceptions. Gifts between family members, for example, would be exempt.

As a representative from Milwaukee, where gun violence spiked in 2015, Harris Dodd called the legislation a “no-brainer.” Milwaukee had 119 gun-related homicides and 633 nonfatal shootings in 2015, according to the Milwaukee Homicide Review Commission — the highest in at least 10 years. The Center has reported that such crimes cost individuals and the state of Wisconsin billions a year in medical bills, police and prosecutorial costs, lost lives and stunted futures.

Of the known suspects in the 2015 gun homicides in Milwaukee, 69 percent — or 66 suspects — were legally prohibited from possessing a firearm at the time of the crime, according to the commission.

Milwaukee’s lobbyist, Jennifer Gonda, said universal background checks are a key part of the city’s legislative agenda. But she is not optimistic any of the city’s priorities to reduce gun violence will pass the current Legislature.

“We didn’t make much headway with the Democrats and … we’re making less with the Republicans,” Gonda said. “In some ways, it feels like we’re spinning our wheels a little bit.”

Milwaukee County Sheriff David Clarke, a member of the NRA, has opposed universal background checks and other gun regulations. Clarke, a Democrat who spoke at the Republican National Convention, has advised residents to arm themselves to stay safe.

“Universal background checks and limiting magazine capacity are offered as reasonable approaches to reducing violence” but are “technical fixes” that mostly “frustrate the overwhelming number of law-abiding American gun owners,” Clarke wrote in an opinion piece for CNN in 2014.

Elvin Daniel said some steps toward reducing gun violence in Wisconsin have been taken. He appeared with Walker in 2014 when the governor signed a law requiring people served with restraining orders to surrender their firearms.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

But for now, universal background checks — which Daniel believes would have prevented the Azana Spa mass shooting that claimed three lives including his sister’s — remain out of reach. He is reminded of that every day by the purple bracelet that reads “For the love of Zina” on his wrist.

“Had he gone through a background check, he wouldn’t have been able to buy a gun,” Daniel said. “Chances are, Zina would still be with us right now.”