An enhanced video more clearly shows boot camp guards manhandling a teenager who later died, including striking the limp boy with closed fists on his forearm.

The tape is among more than 20,000 pages of evidence released Wednesday by prosecutors in the case against the seven former juvenile boot camp guards who were videotaped manhandling 14-year-old Martin Anderson and a nurse who observed it.

The 34-minute video, which is still grainy and overexposed, shows guards repeatedly hauling the boy to his feet and knees and then pinning him face down on the ground at the Bay County sheriff's boot camp in Panama City. The guards haul him up against a pole and apparently throw water in his face.

They also appear to be holding a white cloth to his face.

The guards and the nurse entered not guilty pleas last month to charges stemming from Anderson's death.

Tallahassee attorney Ben Crump, who represents Anderson's parents, Gina Jones and Robert Anderson, in their lawsuit against the state, released the video.

The incident led to the arrest of seven guards and a nurse and forced the state to shut down boot camps, which were overseen by sheriffs' departments and the Department of Juvenile Justice.

Florida Department of Law Enforcement chief Guy Tunnell, who established the boot camp when he was Bay County sheriff, also resigned after making derogatory remarks about national black leaders who came to Tallahassee demanding arrests in the case.

He was also under fire after being scolded by then-Gov. Jeb Bush for exchanging e-mails with current Sheriff Frank McKeithen, criticizing those who questioned the effectiveness of the boot camp concept.

Exactly one year after the incident, on Jan. 5, newly elected Gov. Charlie Crist named former Tallahassee Police Chief Walt McNeil as the new secretary of the Department of Juvenile Justice.

Eight workers at the now-closed Bay County sheriff's boot camp previously on trial said Anderson collapsed while doing exercises there. The guards said they were trying to revive him, but his family and others were outraged at the footage showing the boy pummeled. He died soon after.

But a 30-minute security videotape from the Panama City camp released last year showed guards Charles Helms Jr., 50; Henry Dickens, 50; Charles Enfinger, 33; Patrick Garrett, 30; Raymond Hauck, 48; Henry McFadden Jr., 33; and Joseph Walsh II, 35. Nurse Kristin Schmidt is seen on the video watching and doing nothing to stop.

The local medical examiner found Anderson died of natural complications of sickle cell trait, a usually benign blood disorder. But after cries of a cover-up and the appointment of a special prosecutor, a second autopsy said he was suffocated by the guards' hands over his mouth and the "forced inhalation of ammonia fumes."

Anderson was black and most of the guards and nurses are white, sparking complaints of racism. Students from historically black Florida A&M University held a protest last year targeting former Gov. Jeb Bush.

The boy's family sued the sheriff's office and the state Department of Juvenile Justice, which oversaw the camp system. A judge last year ruled that the $40 million wrongful death lawsuit must wait for the state's criminal case against the guards to conclude.