After Congress failed to pass gun reform last year, the debate over gun violence and Second Amendment rights has largely moved from Washington DC to state capitals. That debate heated up after the December 2012 shooting tragedy at Sandy Hook elementary school in Newtown, Connecticut.

Last year, lawmakers in Connecticut and Colorado – another state rocked by a mass shooting in 2012 – passed sweeping new gun-control measures. In January 2013, New York enacted a law banning high-capacity magazines and the sale of so-called assault weapons, although gun owners and retailers have found a very simple workaround to make their weapons legal.

New research published by the Johns Hopkins Center for Gun Policy and Research found that in the year following the Newtown school shooting, 15 states and the District of Columbia (the site of the navy yard mass shooting in September 2013) strengthened their gun laws, accounting for 44% of the US population. But that same year many states moved in the opposite direction, adopting laws that expanded gun owners’ rights and ensured more protections under the Second Amendment.

To a degree, such debates have carried over into the 2014 legislative sessions. And as those legislative sessions wind down, a few notable gun bills have made their way to the desks of governors around the country.

Here is a snapshot of how the multimillion-dollar debate over gun legislation has played out this year.

Georgia

The Georgia governor, Nathan Deal, gave the National Rifle Association (NRA) a reason to celebrate, days ahead of its annual conference this weekend in Indianapolis.

On Wednesday Deal, a Republican, signed into law what critics dubbed the “guns everywhere” bill, and which the NRA labelled “the most comprehensive pro-gun legislation in state history”.

Under the law, holders of concealed carry permits can bring their firearms into a wide range of public places, including bars, churches and government buildings, under certain circumstances.

The law, set to take effect on 1 July, also allows hunters to use silencers and authorises schools to allow staff to carry weapons on campus.

The bill sparked a heated and high-profile debate, drawing criticism from the former Arizona congresswoman Gabby Giffords, who survived a mass shooting in 2011. Giffords's group, Americans for Responsible Solutions, wrote on its website: "The bill is extremism in action; it moves Georgia out of the mainstream.”

The bill was originally broader in scope, and was scaled back to ensure passage. Initially, it included a controversial “campus carry” provision that would have legalised carrying guns on campuses. Another provision would have permitted guns in places of worship unless religious leaders specifically barred them. Instead, the new law gives religious leaders the option to “opt-in” to allowing guns into their churches.

Deal – who touts a grade-A approval rating from the NRA – told a crowd of pro-gun advocates who gathered to watch him sign the bill into law: "The Second Amendment should never be an afterthought. It should be at the forefront of our minds."

Arizona

In Arizona, the conservative governor, Jan Brewer, again revealed a moderate streak when she vetoed NRA-backed legislation that would have allowed gun owners to carry firearms into some public buildings. This is the third time in four years Brewer has vetoed such legislation.



In her veto statement, Brewer said: "I am a strong proponent of the Second Amendment, and I have signed into law numerous pieces of legislation to advance and protect gun rights. However, I cannot support this measure in its proposed form."

Brewer’s veto record on such legislation has caused some gun-rights supporters to question her commitment to protecting the Second Amendment.

Co-founder of Arizona Citizens Defense League Charles Heller told Reuters his group "expected better from someone who was rumoured to be an ally of freedom".

Brewer also vetoed a bill that would have punished local officials for enacting gun statutes that are more strict than state law, and another bill that would make it an aggravated assault crime to take a gun away from another person with the intent to cause harm with that gun. Still on the table is a technical bill that would modify the definition of a firearm to exclude air rifles.

Kansas

Kansas passed a new law on Wednesday, stripping local governments of their ability to restrict the state’s open-carry law. This law, which goes into effect in July, awards the state sole power over regulating firearms. It pre-empts counties, cities and municipalities from restricting firearm sales or regulating how guns are stored and transported. Cities and counties, however, will still be allowed to prevent people from carrying weapons in public buildings.

“Kansans have long believed the right to bear arms is a constitutional right,” Kansas's governor, Sam Brownback, said in a statement after signing the bill, the Wichita Eagle reported.

The law is meant to ensure Kansas’s open-carry law is upheld in every corner of the state, a priority of gun-rights proponents. The NRA promoted the new Kansas law as a model for how other states should restrict local governments' gun-regulating authority. Similar legislation has been introduced and debated in several states.

The law also bars people from carrying and firing a gun while intoxicated – a provision that was modelled after laws against drunk-driving. But the measure does not apply to someone who uses a gun in self-defence or to protect another person, even if that person is impaired. This exemption and the law’s vague language have some critics worried it could actually protect people who fire a weapon while under the influence of drugs or alcohol.

Last year, Kansas made waves by passing laws that expanded the list of public places in which concealed carry permit holders can pack heat, which included a provision authorising schools to allow employees to arm themselves.

Colorado

A police officer stands in front of an Aurora, Colorado, home in which four people were killed, including the gunman, in 2012. Photograph: Marc Piscotty/Getty Images

Colorado found itself in the crosshairs of gun rights groups last year when the Democratic governor, John Hickenlooper, signed into law sweeping new gun restrictions. For this reason, advocates from all sides of the gun debate kept a close eye on gun bills introduced during the 2014 legislative session.

Last year’s controversial gun package put in place tough new restrictions that expanded background checks on private sales and limits on ammunition magazines, among other provisions. Fallout from the law saw two Democratic lawmakers ousted from office in a recall election and another resign to avoid the possibility of a similar fate. It also prompted one of the nation’s largest gun manufacturers to move its operations from Colorado to Wyoming and Texas. The law has been challenged in court, and a federal judge will determine if it violates Colorado residents' constitutional right to bear arms.

This year, Republican state lawmakers introduced a slew of bills aimed at rolling back or repealing last year’s law. But it was to no avail. Their efforts were blocked repeatedly by Democrats who still control the legislature. One bill would have repealed the law’s requirement that non-licensed gun dealers must obtain a background check and receive approval from the Colorado Bureau of Investigation before transferring a firearm, among other provisions.

So far, the state has approved only one relatively minor change to the state’s gun laws. Hickenlooper signed a bipartisan measure that tweaks existing law to allow gun owners to renew their carry permits at any sheriff’s office, as opposed to the office where the permit was issued.

South Dakota

The Republican-controlled legislature passed a rare gun-related bill that found support among groups typically in fierce opposition.



In March, South Dakota’s governor, Dennis Daugaard, signed into law a bill that will add the names of certain people who are mentally ill to the National Instant Criminal Background Check System, in an effort to keep them from buying guns.

The bill, signed just weeks before the killings at Fort Hood that reignited a national debate about mental health and gun control, was backed by the NRA as well as other groups that aim to prevent gun violence. The NRA has taken the stance that mental illness, as opposed to lax gun laws, is the root cause of America’s mass shootings. The NRA has supported similar legislation around the country. The bill also lays out a channel for individuals to have certain rights to bear arms restored by a court.

Best practices on how to keep guns out of the hands of mentally ill individuals is likely to remain a topic of discussion at the state and national level. Just this year, the Consortium for Risk-Based Firearms Policy crafted policy recommendations that, among other things, calls for temporary restrictions of up to five years on the purchase and possession of firearms by people who have been convicted of violent misdemeanours, domestic violence or more than one drug or alcohol conviction within a certain period.

“A data-driven approach should also extend to the way we think about mental illness and gun violence,” said Jeffrey Swanson, a professor in psychiatry and behavioural sciences in a statement from the Johns Hopkins Center for Gun Policy and Research.