CHICAGO » Not a single gun shop can be found in this city because they are outlawed.

Handguns were banned in Chicago for decades, too, until 2010, when the U.S. Supreme Court ruled that was going too far, leading city leaders to settle for restrictions some describe as the closest they could get legally to a ban without a ban. Despite a continuing legal fight, Illinois remains the only state in the nation with no provision to let ordinary people carry guns in public.

And yet Chicago, a city with no civilian gun ranges and bans on both assault weapons and high-capacity magazines, finds itself laboring to stem a flood of gun violence that contributed to more than 500 homicides last year and at least 40 killings already in 2013, including a fatal shooting of a 15-year-old girl on Tuesday.

To gun rights advocates, the city provides stark evidence that even some of the toughest restrictions fail to make places safer.

"The gun laws in Chicago only restrict the law-abiding citizens and they’ve essentially made the citizens prey," said Richard A. Pearson, executive director of the Illinois State Rifle Association.

To gun control proponents, the struggles here underscore the opposite — a need for strict, uniform national gun laws to eliminate the current patchwork of state and local rules thatallow guns to flow into this city fromoutside.

"Chicago is like a house with two parents that may try to have good rules and do what they can, but it’s like you’ve got this single house sitting on a whole block where there’s anarchy," said the Rev. Ira J. Acree, one among a group of pastors here who have marched and gathered signatures for an end to so much shooting. "Chicago is an argument for laws that are statewide or, better yet, national."

Chicago’s experience reveals the complications inherent in carrying out local gun laws around the nation. Less restrictive laws in neighboring communities and states not only make guns easy to obtain nearby, but layers of differing laws — local and state — make it difficult to police violations.

And though many describe the local and state gun laws here as relatively stringent, penalties for violating them — from jail time to fines — have not proven as severe as they are in some other places, reducing the incentive to comply.

Lately, the police say they are discovering far more guns on the streets of Chicago than in the nation’s two more populous cities, Los Angeles and New York. They seized 7,400 guns here in crimes or unpermitted uses last year (compared with 3,285 in New York City), and have confiscated another 574 guns just since Jan. 1 — 124 of them last week alone.

More than a quarter of the firearms seized on the streets here by the Chicago Police Department over the past five years were purchased just outside city limits in Cook County suburbs, according to an analysis by the University of Chicago Crime Lab. Others came from stores around Illinois and from other states, like Indiana, less than an hour’s drive away.

Since 2008, more than 1,300 of the confiscated guns, the analysis showed, were purchased from just one store, Chuck’s Gun Shop in Riverdale, Ill., within a few miles of Chicago’s city limits.

Efforts to compare the strictness of gun laws and the level of violence across major U.S. cities are fraught with contradiction and complication, not least because of varying degrees of coordination between local and state laws and differing levels of enforcement.

In New York City, where homicides and shootings have decreased, the gun laws are generally seen as at least as strict as Chicago’s, and the state laws in New York and many of its neighboring states are viewed as still tougher than those in and around Illinois.

Philadelphia, like cities in many states, is limited in writing gun measures that go beyond those set by Pennsylvania law. Some city officials there have chafed under what they see as relatively lax state controls, even as they have wrestled with a stream of homicides.

In Chicago, the rules for owning a handgun — rewritten after the outright ban was deemed too restrictive in 2010 — sound arduous. Owners must seek a Chicago firearms permit, which requires firearms training, a background check and a state-mandated firearm owners identification card, which requires a different background review for felonies and mental illness.

To prevent straw purchasers from selling or giving their weapons to people who would not meet the restrictions — girlfriends buying guns for gang members is a common problem, the police here say — the city requires permitted gun owners to report their weapons lost, sold or stolen.

Still, for all the regulations, the reality here looks different. Some 7,640 people currently hold a firearms permit, but nearly that many illicit weapons were confiscated from the city’s streets during last year alone.

Chicago officials say Illinois has no requirement, comparable to Chicago’s, that gun owners immediately report their lost or stolen weapons to deter straw purchasers. Consequently those outside the city can, in the words of one city official, carry guns to gang members in the city with "zero accountability."

And a relatively common sentence in state court for gun possession for offenders without other felonies is one year in prison, which really may mean a penalty of six months, said Anita Alvarez, the Cook County state’s attorney. She said such punishments failed to serve as a significant enough deterrent for seasoned criminals who may see a modest prison stint as the price of doing business.

"The way the laws are structured facilitates the flow of those guns to hit our streets," Garry F. McCarthy, the Chicago Police superintendent, said in an interview, later adding, "Chicago may have comprehensive gun laws, but they are not strict because the sanctions don’t exist."

In the weeks since the mass shooting in Newtown, Conn., Toni Preckwinkle, the Cook County Board president, has introduced a countywide provision requiring gun owners beyond the city limits to report lost or stolen guns, though a first offense would result simply in a $1,000 fine. In the city, Mayor Rahm Emanuel has pressed for increased penalties for those who violate the city’s gun ordinance by failing to report their guns missing or possessing an assault weapon.

"Our gun strategy is only as strong as it is comprehensive, and it is constantly being undermined by events and occurrences happening outside the city — gun shows in surrounding counties, weak gun laws in neighboring states like Indiana and the inability to track purchasing" Emanuel said. "This must change."

State lawmakers, too, are soon expected to weigh new state provisions like an assault weapons ban, as Chicago already has. But the fate of the proposals is uncertain in a state with wide-open farming and hunting territory downstate.

"It’s going to be a fight," said state Rep. Jack D. Franks, D-Marengo, 60 miles outside Chicago.

Complicating matters, an appellate court in December struck down the state’s ban on carrying guns in public, saying that a complete ban on concealed carry is unconstitutional. Illinois is seeking a review of the ruling, even as state lawmakers have been given a matter of months to contemplate conditions under which guns could be allowed in public.

Many here say that even the strictest, most punitive gun laws would not alone be an answer to this city’s violence.

"Poverty, race, guns and drugs — you’ve got to deal with all these issues, but you’ve got to start somewhere" said the Rev. Jesse L. Jackson Sr., who was arrested in 2007 while protesting outside Chuck’s Gun Shop, the suburban store long known as a supplier of weapons that make their way to Chicago.

At the store, a clerk said the business followed all pertinent federal, state and local laws, then declined to be interviewed further.

Among seized guns that had moved from purchase to the streets of Chicago in a year’s time or less, nearly 20 percent came from Chuck’s, the analysis found. Other guns arrived here that rapidly from gun shops in other parts of this state, Indiana, Wisconsin, Kentucky, Mississippi, Georgia, Iowa and more.

"Chicago is not an island," said David Spielfogel, senior adviser to Emanuel. "We’re only as strong as the weakest gun law in surrounding states."

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