( CNN ) -- Florida law kept George Zimmerman from being held accountable in last year 's shooting death of Florida teenager Trayvon Martin , the teen 's mom said Friday . `` Wrap your mind around no prom for Trayvon , no high school graduation for Trayvon ... all because of a law -- a law that has prevented the person who shot and killed my son '' from paying `` for this awful crime , '' Sybrina Fulton said Friday afternoon at the National Urban League Conference in Philadelphia . Zimmerman , a former neighborhood watch volunteer , was found not guilty in the 17-year-old Martin 's death on July 13 . Father : Let 's turn negative energy into positive . He fatally shot Martin in the Sanford , Florida , neighborhood where Zimmerman and Martin 's father lived in February 2012 . Zimmerman , who is Hispanic , had a confrontation with the unarmed African-American teen after calling police to report a suspicious person , and he said he shot Martin in self-defense . The case became a flashpoint in debates over racial profiling , and thousands attended vigils across the country over the weekend , decrying the verdict . Zimmerman juror to ABC : He 'got away with murder ' Fulton asked attendees of the National Urban League gathering Friday to use her `` broken heart '' to ensure `` there are no more Trayvon Martins again . '' `` My message to you is : Please use my story . Please my use my tragedy . Please use my broken heart to say to yourself , 'We can not let this happen to anybody else 's child , ' '' she said . 'Boycott Florida , ' is n't so simple , experts say .
Trayvon Martin 's mother addresses the National Urban League Conference . The NAACP is a civil rights organization that works to improve conditions for African Americans and other minority groups in America. Fulton : ` ` Use my broken heart '' to prevent something like this from happening again .