Sybrina Fulton, the mother of Trayvon Martin, testified before a Senate hearing Tuesday that so-called "stand your ground" laws demand clarity.

Two Florida mothers whose unarmed sons were shot to death gave emotional testimony Tuesday at a Senate panel, demanding that states alter their "stand your ground" laws.

Sybrina Fulton described how the family had just celebrated her son Trayvon Martin's 17th birthday three weeks before he was killed in the Retreat at Twin Lakes, a gated community in Sanford, Fla.

"He was simply going to get a drink and some candy. That tells me right there, his mentality. That tells me that he was not going to get cigarettes or bullets or condoms or other items of that nature," she told a packed Senate Judiciary Committee hearing. "Trayvon was minding his own business."

"So I just wanted to come here to talk to you for a moment to let you know how important it is that we amend this stand-your-ground because it did not work in my case. The person that shot and killed my son is walking the streets today, and this law does not work. We need to seriously take a look at this law," she said.

Stand-your-ground laws are on the books in at least 22 states and change the legal definition of self-defense for citizens who feel they are being confronted with deadly force or imminent danger, canceling their duty to retreat. But Fulton argued at the hearing that the Feb. 26, 2012, shooting of her son and the acquittal of George Zimmerman over the summer shows that the laws are confusing.

Also testifying was Lucia Holman McBath, who wore a pin with a photo of her only child, Jordan Russell Davis, affixed to her chest.

Lucy McBath says the man that shot and killed her son was empowered by the Stand Your Ground statue adding, "I am here to tell you that there was no ground to stand, there was no threat."

Davis, 17, was killed nearly a year ago when Michael David Dunn, 46, allegedly fired nine rounds on a Dodge Durango with four teenagers inside in Jacksonville, Fla., after complaining about their loud music and claiming he saw a gun. Authorities never found a gun inside.

McBath, struggling to hold back tears at one point, told the committee that Dunn sprayed the vehicle with bullets, then went back to his hotel and ordered a pizza. She said he wasn't arrested until the following morning.

"That man was empowered by the 'stand your ground' statute," McBath said. "I am here to tell you there was no ground to stand. There was no threat. No one was trying to invade his home, his vehicle, nor threatened him or his family."

Dunn's trial has been delayed until next year, but McBath said she faces the "very real possibility that my son's killer will walk free, hiding behind a statute that lets people claim a threat where there was none."

"Even the Wild West had more stringent laws governing the taking of life than we have now. Stand-your-ground defies all reason. It goes against the sound system of justice established long ago on this very hill," she said.

McBath described her son to the committee: "I can tell you all about him. His easy smile, his first girlfriend, and his plans to join the Marines."

"But you can never really know my boy because an angry man who owned a gun kept it close at hand and chose to demonstrate unbridled hatred one balmy evening for reasons I will never understand," she said.

Florida had the first stand-your-ground law, passed in 2005.

"Trayvon and Jordan didn't ask to be martyrs. The American legal system made them martyrs," Rep. Marcia Fudge, D-Ohio, said at the hearing. "Stand-your-ground laws eliminate all responsibility to retreat and peacefully end an incident."

Sen. Dick Durbin, D-Ill., led the inquiry, calling two panels of witnesses to the hearing room on Tuesday to discuss the issue. The Senate is holding the hearing even though no congressional action is expected on the state policies, according to the AP.

In opening the hearing on Tuesday, Durbin said, "It is clearly time for stand-your-ground to be carefully reviewed."

"These stand-your-ground laws have led to increases in homicides and firearms injuries," he said. "These stand-your-ground laws have allowed shooters to walk free in shocking situations."

On the other side of the discussion was Sen. Ted Cruz, R-Texas, who questioned what role federal government had in interfering with a state issue.

"Self-defense is a bedrock liberty of every American, and I would note this is not a new concept," he said, citing the Second Amendment.

Stand your ground laws are sometimes referred to as "Shoot First" laws by detractors. They were part of the public discussion around the Zimmerman trial; although the legal team arguing on behalf of Zimmerman did not ask for an immunity hearing under the law, the instructions given to the jury borrowed language from the statute.

Normally, a citizen has a duty to retreat when confronted with what they perceive to be deadly force. The stand your ground doctrine mostly removes that, meaning citizens who feel threatened are no longer required to try to quell a situation first before having the right to use deadly force in self-defense.

Gun rights groups, like the National Rifle Association, argue stand your ground laws are about protecting the right to self-defense.

Also testifying at the hearing was Rep. Louie Gohmert, R-Texas, a strong supporter of stand your ground laws.

Gohmert pointed out to Durbin and others in the hearing that murder rates are higher in Chicago and Washington, D.C., than they are in states that have stand-your-ground laws.

"[The] idea of being able to stand one's ground without first retreating has been combined as part of the law of self-defense in at least 22 states. It might also be noted that these 22 are not necessarily states in which runaway murder rates abound," he said.

The Associated Press contributed to this report.

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