ORLANDO, Florida (WKMG) - State Attorney Norm Wolfinger announced Tuesday that the Seminole County grand jury will convene April 10 regarding the federal investigation into the shooting death of 17-year-old Trayvon Martin.
Related: Stand your ground law explained
Martin was shot and killed last month in a confrontation with neighborhood watch leader George Zimmerman while walking from a store in Sanford after purchasing a bag of Skittles and an iced tea.
Photo Gallery: FL teen killed by neighborhood watch volunteer
The U.S. Justice Department announced Monday night that it has also opened an investigation. Wolfinger's office said in a release the Florida Department of Law Enforcement's involvement investigation began on Friday.
Zimmerman, 28, has not been arrested or charged after claiming he shot Martin in self-defense. The state attorney's office is reviewing the case.
Zimmerman called police to report a suspicious person after he saw Martin walking back from the store. Police instructed him not to confront Martin, but a confrontation ensued. Zimmerman shot the unarmed teen in the chest.
Police also released more calls on Monday that Zimmerman made to authorities while on neighborhood watch leading up to Martin's death.
Martin's family and others have demanded that Zimmerman be arrested, urging a federal investigation into the shooting.
"The (Department of Justice) will conduct a thorough and independent review of all of the evidence and take appropriate action at the conclusion of the investigation," the agency said in its statement. "The department also is providing assistance to and cooperating with the state officials in their investigation into the incident. With all federal civil rights crimes, the government must prove beyond a reasonable doubt that a person acted intentionally and with the specific intent to do something which the law forbids -- the highest level of intent in criminal law. Negligence, recklessness, mistakes and accidents are not prosecutable under the federal criminal civil rights laws. The Community Relations Service will be in Sanford, Fla., this week to meet with civil rights leaders, community leaders and local law enforcement to address tension in the community."
Also on Monday, Gov. Rick Scott requested the Florida Department of Law Enforcement assist the state attorney's office in its investigation after the case "caused significant concern within the Sanford community and the state."
Meanwhile, an online petition created by Martin's parents has garnered more than 425,000 signatures, including several from celebrities.
The change.org petition, started by Tracy Martin and Sybrina Fulton, calls for the Florida district attorney to file charges against Zimmerman.
Among those who have signed the petition are: Clay Aiken, Spike Lee, Chad Ochocinco, Alyssa Milano and Russell Simmons.
"Let's seek justice for Trayvon Martin. We will fight for a society that is compassionate and loving, not one that pre-judges and stereotypes," Simmons recently tweeted.
Photo Gallery: Trayvon Martin photos
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