WASHINGTON -

Sybrina Fulton, the mother of Trayvon Martin, and Lucia McBath, mother of Jordan Davis, are telling a Senate panel Tuesday that states must clarify their "stand your ground" self-defense laws.

The laws, adopted in Florida in 2005 and since passed in some form by at least 21 other states, generally cancel a person's duty to retreat in the face of a serious physical threat. But the 2012 shooting of Fulton's unarmed son, Trayvon Martin, 17, in a Sanford, Fla., neighborhood and the acquittal of George Zimmerman this year provided evidence that "stand your ground" laws can be confusing and applied inconsistently, she said.

"By being unclear in when and how it is applied, stand your ground in its current form is far too open to abuse," Fulton said in prepared testimony for the Senate Judiciary Committee.

"The person who shot and killed my son is walking the streets today, and this law does not work," Fulton said. "We need to seriously look at this law and speak with the state attorney's office and police departments."

McBath is the mother of Jordan Davis, the 17-year-old killed nearly a year ago when Michael Dunn, 46, allegedly opened fire on a Dodge Durango with four teenagers inside after complaining of their loud music and saying he saw a gun.  Authorities never found a gun in the vehicle.

"That man was empowered by the 'stand your ground' statute," McBath said in prepared testimony. "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.

Senate leaders told both mothers they've done some research of their own. The stand your ground law has led to an average of 600 additional homicides a year, with no deterrent effect on robbery or assaults. They say the law has emboldened those who carry guns to initiate confrontations, knowing they can use the law as their defense.

"This law declares open season on anyone we don't trust for reasons we don't understand. They don't even have to be true," McBath said. "In essence, it allows any armed citizen to self-deputize themselves and establish their own definition of law and order."

The Democratic-led Senate was holding the hearing even though no congressional action is expected on the state policies. Even in the states, Martin's killing, Zimmerman's politically charged acquittal on manslaughter charges and encouragement from the Obama administration seem unlikely to spur changes in "stand your ground" laws. Most states with such laws are conservative and lean toward policies that defend gun owners' rights.

Sen. Dick Durbin opened the hearing by saying the laws have been abused and urging Congress to consider how the policy would affect other gun legislation. Texas Republican Sen. Ted Cruz said the laws make possible the right to self defense.

According to the National Conference of State Legislatures, states have laws that allow that "there is no duty to retreat (from) an attacker in any place in which one is lawfully present" include: Alabama, Arizona, Florida, Georgia, Indiana, Kansas, Kentucky, Louisiana, Michigan, Mississippi, Montana, Nevada, New Hampshire, North Carolina, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah and West Virginia.

At least nine of those state laws include language stating one may "stand his or her ground": Alabama, Florida, Georgia, Kansas, Kentucky, Louisiana, Oklahoma, Pennsylvania and South Carolina, according to the NCSL.
    
Gun rights groups such as the National Rifle Association say "stand your ground" laws are about self-defense.
    
"Self-defense is not a concept, it's a fundamental human right," said Chris W. Cox, executive director of the NRA's Institute for Legislative Action.