Meanwhile, Martin's parents are blaming police for leaking information about their son being suspended for marijuana and details about the fight he had with Zimmerman that portrayed the teen as the aggressor.
Martin's mother, Sybrina Fulton, and family attorneys said Monday that it was part of an effort to demonize her son.
"They killed my son and now they're trying to kill his reputation," Fulton told reporters.
Martin was suspended by Miami-Dade County schools because traces of marijuana were found in a plastic baggie in his book bag, family spokesman Ryan Julison said. Martin was serving the suspension when he was shot Feb. 26.
The Sanford Police Department insisted there was no authorized release of the new information but acknowledged there may have been a leak. City Manager Norton Bonaparte Jr. said it would be investigated and the person responsible could be fired.
Martin family attorney Benjamin Crump said the link between the youth and marijuana should have no bearing on the probe into his shooting death. State and federal agencies are investigating, with a grand jury set to convene April 10.
"If he and his friends experimented with marijuana, that is completely irrelevant," Crump said. "What does it have to do with killing their son?"
The state Department of Juvenile Justice confirmed Monday that Martin does not have a juvenile offender record. The information came after a public records request by The Associated Press.