CAMBRIDGE, Mass. -

The mother of Trayvon Martin will speak Monday at Harvard Law School about changing "stand your ground" self-defense laws.

Sybrina Fulton will be joined by her attorney, Benjamin Crump.

George Zimmerman was acquitted of second-degree-murder in the death of 17-year-old Trayvon Martin in July.

Since his death, Fulton has been speaking out against the controversial law.

Last month, she told a panel of U.S. senators that the laws don't work and must be amended. Democrat have supported Fulton's call. Republicans said it should be left to the states that passed the laws.

According to the National Conference of State Legislatures, at least 22 states have laws that allow that "there is no duty to retreat (from) an attacker in any place in which one is lawfully present."