Trayvon Martin's Mother to Speak in Philadelphia

Along with Eric Holder at an annual National Urban League conference

The mother of slain Florida teenager Trayvon Martin and U.S. Attorney General Eric Holder will speak in Philadelphia this week at the National Urban League's annual conference.

Civil rights and voting rights are two major topics of the four-day event, which begins Wednesday. About 6,000 participants are expected.

Holder will talk Thursday about a recent Supreme Court ruling that struck down a key provision of the Voting Rights Act.

Martin's mother, Sybrina Fulton, will speak Friday. She supports an investigation into whether her son's killer could be charged under federal civil rights laws. A jury acquitted George Zimmerman of all criminal counts in Martin's death.