Two weeks before the opening of George Zimmerman’s much-watched trial for the murder of Trayvon Martin, Ohio’s legislature introduced legislation to expand its version of the Florida law that allows residents to use deadly force if they believe they are in imminent danger, as Zimmerman convinced a jury he did.

A search using the Sunlight Foundation’s Open States shows that Ohio is one of two states (the other is Iowa) that have introduced bills this year to expand laws similar to the Florida “stand your ground” law. That suggests that the statute, which last year created an enormous public relations problem for the pro-business group that promoted it, may be becoming less toxic.

The stand your ground law played an important role in the early stages of the Trayvon Martin murder case, although defense attorney Mark O’Mara did not rely on it in winning Zimmerman’s acquittal last week, and many states have similar laws on the books. The map indicates states where Sunlight has found self-defense laws (almost all of them). Those that have passed statues most similar to Florida’s are highlighted in yellow.

Because Zimmerman claimed self defense immediately following the shooting of Martin, an unarmed teenager, police in Florida initially could not arrest him. Indeed, police even slowed their investigation, citing the state’s stand your ground law. It was only after a public outcry that he was taken into custody. Last week, a Florida jury found Zimmerman not guilty of second-degree murder.

Florida’s stand your ground law allows individuals who are in any place they have a legal right to be to use deadly force if they feel threatened with bodily harm or death even if they had the ability to flee the confrontation. The term commonly used for not having to try to get away to safety is referred to in legislation as “no duty to retreat.” Stand your ground laws are extensions of the “castle doctrine,” which permit the use of deadly force against intruders in one’s home or vehicle without legal consequences.

The American Legislative Exchange Council backed passage of stand your ground laws. The nonprofit consortium works to get legislation enacted at the state level that benefits the bottom lines of its members, which includes some of the wealthiest corporations and some of the most well-heeled special interests in the country. The Florida law that kept Zimmerman from being charged was pushed by the National Rifle Association and Wal-Mart, the country’s largest gun retailer.

The Legal Center Against Violence, which opposes what it describes as Florida’s “Shoot First” law, has found that  26 states have similar laws and seven more permit the use of deadly force with no duty to retreat.

Last year, shortly after Martin was shot, the Sunlight Foundation produced an analysis that looked at which of the stand your ground laws that have been enacted around the country strongly resemble Florida’s law. The analysis was done in order to identify states where ALEC successfully promoted its “model version” of the legislation.

Sunlight ultimately found that of the state laws identified by the LCAV, 15 were strikingly similar to Florida’s law. It’s possible that more bills identified by LCAV were also influenced by the ALEC bill, but it’s also possible that those laws drew on the castle doctrine, an old idea that came about long before ALEC existed. As the map above illustrates, almost every state has laws on the books that allow for some level of self defense when people feel threatened.

Those laws vary widely from state to state in what they permit in the name of self-defense. For instance, in California, people who believe they are in danger of bodily harm have no duty to retreat, can use deadly force and can even chase an assailant until they feel they are safe again. Arkansas’ law says that people do have a duty to retreat unless they are in their home. When people are in their homes they can also use deadly force without trying to flee to safety. Legislation introduced in Iowa in January of this year states that someone who uses deadly force because he or she senses danger can even be wrong about that feeling if there was a reasonable basis for believing so to begin with.

The map included in this post highlights all the states with statutes that seem to have their origins in castle doctrine, the states with laws that Sunlight found to be copies of Florida’s stand your ground legislation and the two states identified through Open States as introducing legislation to expand their castle doctrine laws this year.  There is data for all but two states and the District of Columbia. Those jurisdictions may not have self-defense statutes on the books.

In the wake of the Martin shooting, some members of Congress Florida, as well as Missouri and Texas have called for repeal of stand your ground laws. But none of the legislation they have proposed has made it out of committee.

(Graphic by Ben Chartoff; Kyle Smith contributed to this post.)