Trayvon Martin's mother says states should clarify their ``stand your ground'' self-defense laws.

Sybrina Fulton is telling a Senate committee in Washington Tuesday that the laws, which generally eliminate a person's duty to retreat in the face of a serious physical threat, are confusing and inconsistent. She says neighborhood-watch volunteer George Zimmerman ``got away with murder'' in the 2012 killing of her son, largely because of Florida's policy, although "stand your ground" was not invoked by Zimmerman's defense at trial.

Fulton says stand your ground doesn't mean chase after someone who has turned his back.

In July, a jury acquitted Zimmerman, 29, of all charges in the February 2012 shooting death of Trayvon, who was 17 and unarmed. Some gun control advocates say states should re-examine their laws. But gun rights advocates say that's a swipe at the right to self-defense.

Copyright: AP/Joel Malkin contributed