Sybrina Fulton, the mother of Trayvon Martin, testified on Capitol Hill today that "stand your ground" laws must be reviewed and amended.

"It's unfortunate what has happened with Trayvon, and that's why I feel like it's so important for me to be here so that you all can at least put a face with what has happened with this tragedy," Fulton said at a Senate Judiciary subcommittee hearing today.

"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, certainly did not work in my case," she said. "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."

In 2012, Trayvon Martin, 17, was unarmed when he was shot and killed by George Zimmerman, who was acquitted of the murder this summer. Although Zimmerman's defense did not invoke the stand your ground law, the case sparked a national debate about race and "stand your ground" laws, which exist in at least 22 states.

The hearing held by a subcommittee of the Senate Judiciary Committee today examined the impact of "stand your ground" laws. The hearing was initially supposed to be held last month but was delayed to the shootings at the Navy Yard in Washington, D.C.

Sen. Dick Durbin, chairman of the Constitution, Civil Rights and Human Rights subcommittee, said the self-defense laws have caused "unnecessary tragedies" and need to be reviewed.

"It is clearly time for 'stand your ground' laws to be carefully reviewed and reconsidered," Durbin said. "Whatever the motivation behind them, it's clear these laws often go too far in encouraging confrontations that escalate into deadly violence. They're resulting in unnecessary tragedies and they are diminishing accountability under our justice system."

But several Republicans at the hearing said the laws should not be dealt with on the federal level and must be left to the states.

"If it is not within Congress's jurisdiction to legislate substantive state criminal law, it raises whether there may perhaps be a broader political agenda behind the hearing instead," Sen. Ted Cruz, R-Texas, said. "This is not about politicking. This is not about inflaming racial tensions, although some might try to use it to do that. This is about the right of everyone to protect themselves, to protect their family."

"With only a few exceptions most states are doing quite well with legislating in the area of criminal law without our interference," said Rep. Louie Gohmert, R-Texas. "Let's leave state criminal law to the consideration of the state legislatures that we in Congress would probably be well served to take advice from the states that are still solvent."