SANFORD, Fla. -

A slain Florida teenager and the neighborhood watch captain who shot and killed him exchanged words before the teen punched him in the nose and began banging the man's head on the ground, according to the watch captain's account of the confrontation that led to the shooting. 

The Orlando Sentinel reported that George Zimmerman told police he lost 17-year-old Trayvon Martin in the neighborhood he regularly patrolled and was walking back to his vehicle last month when the youth approached him from behind. 

The two exchanged words, Zimmerman said, and Martin then punched him, jumped on top of him and began banging his head on a sidewalk. Zimmerman said he began crying for help; Martin's family thinks it was their son who was crying out. Witness accounts differ and 911 tapes in which the voices are heard are not clear. 

A statement from Sanford police said the newspaper story was "consistent" with evidence turned over to prosecutors. 

Because Martin was black and Zimmerman has a white father and Hispanic mother, the case has become a racial flashpoint that has civil rights leaders and others leading a series of protests in Sanford and around the country. Zimmerman said he shot Martin in self-defense and has not been arrested. 

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. 

Despite the news of Martin's possible actions the night of the shooting, rallies demanding the arrest of the 28-year-old Zimmerman spread from Florida to Indiana.