TALLAHASSEE, Fla. -

As the Florida Legislature returns to Tallahassee this week, the debate over the state's controversial "stand your ground" self-defense law is returning as well, with a five-hour hearing scheduled for Thursday and both sides already at work getting their messages out.

The House Criminal Justice Subcommittee will take up a bill by Rep. Alan Williams, D-Tallahassee, that would repeal "stand your ground," and activists who protested the law with a sit-in at the Capitol this summer are expected to turn out in force.

"(It) will be the first time in our country that any legislature has taken up a bill to repeal 'stand your ground,' " Williams said during a conference call with supporters Sunday.

Florida's law, which became a model for similar statutes in other states, allows people to use deadly force when they feel their lives are in danger and provides immunity from prosecution or civil lawsuits. The law, an expansion of the traditional "Castle Doctrine," which gives people the right to defend themselves with deadly force in their own homes, also removed the duty to retreat in any place outside the home where the individual has a right to be.

Williams' repeal bill appears to have no chance as lawmakers hold committee meetings to prepare for the 2014 legislative session. The "stand your ground" law is heavily supported in both chambers of the Republican-led Legislature, and House Criminal Justice Chairman Matt Gaetz, R-Fort Walton Beach, has famously said that "not one comma" in the law should be changed.

"If you look at the five years preceding the 'stand your ground' law, each year the murder rate went up in our state," Gaetz said. "Since the 'stand your ground' law passed, the murder rate has gone down. I'm sure there are many reasons that's the case, but I've got to believe that having robust self-defense laws --- that puts the law on the side of the law-abiding citizen, and it puts criminals on notice."

Members of the Dream Defenders, a group that staged the sit-in after George Zimmerman was acquitted in the 2012 shooting death of teen Trayvon Martin, are asking supporters to call the offices of Gaetz and Rep. Ray Pilon, a Sarasota Republican who is vice-chairman of the Criminal Justice Subcommittee, "to let them know how we feel about the 'stand your ground' law."

Martin was walking through a gated community, on his way home from buying a drink and candy, when he was pursued by Zimmerman, a neighborhood-watch volunteer. Zimmerman, who claimed that Martin attacked him first, was acquitted in the shooting death, sparking the 31-day sit-in outside Gov. Rick Scott's office.

Zimmerman claimed he shot Martin in self-defense, but did not use "stand your ground" to avoid being prosecuted. The law, however, spawned changes to jury instructions that at least one Zimmerman juror said resulted in the not-guilty verdict.

During the sit-in, the Dream Defenders asked Scott, Senate President Don Gaetz and House Speaker Will Weatherford to call a special legislative session to review "stand your ground." All refused. The group then forced a poll of lawmakers that ended up well short of the votes needed to support a special session, losing by a 96-45 margin. Weatherford, however, announced that the House would hold a hearing, with Thursday's marathon meeting the result.

The Dream Defenders are calling for removal of the "no duty to retreat" provision of the law.

"(We) believe if there is an opportunity for retreat, there should be a duty to retreat as well, because the 'no duty to retreat' (provision) promotes violence and reckless behavior," said Woodjerry Louis, a student at the University of Florida.

But National Rifle Association lobbyist Marion Hammer said her group would never agree to removing that language from the law.

"One of the primary purposes of passing the Castle Doctrine-'stand your ground' law in 2005 was to remove the duty to retreat, because forcing a law-abiding citizen to defer to a criminal and give preference to a criminal over a victim is just wrong," Hammer said.

The Dream Defenders also say there should be stricter guidelines for granting immunity under "stand your ground."

Participating in Sunday's phone meeting with Williams and the Dream Defenders was Ron Davis, father of 17-year-old, Jordan Davis, who was fatally shot last year in Jacksonville.

In a case that has drawn widespread attention, the shooting took place at a gas station, where 45-year-old Michael Dunn told a carload of four young men to turn down their loud music and, after an argument, opened fire. Dunn has pleaded not guilty, saying he feared for his life and saw a weapon in the other car, but police have said Jordan Davis and his friends were unarmed.

"I see kids on the street that look like my son, and I just cry," Ron Davis said Sunday. "I see kids in the park playing basketball and I cry. I wait for my kid to come home and put the key in the door at night, and when he doesn't, I cry."

Dunn faces trial on murder and attempted murder charges. Last week, Davis' mother, Lucia McBath, told a U.S. Senate hearing on "stand your ground" that she feared the law would be used to exonerate her son's killer.

But gun-rights supporters say the deaths of Davis and Martin are being used to attack the law based on emotion, not fact.