TALLAHASSEE - The noted pathologist who reviewed the autopsy of Martin Lee Anderson told lawmakers Friday he thinks the teenager died because he could not breathe as he was punched and kicked by guards at a Panhandle boot camp.

Last week, Dr. Michael Baden said Anderson did not die of natural causes, contradicting the initial autopsy that ruled his death the result of a genetic disorder. Then Friday, he further clarified his position in a telephone conference call to a legislative committee studying boot camps.

"He didn't have any rupture of internal organs," Baden said, meaning the kicks and punches themselves did not cause death.

"He did have a number of situations in which his breathing was impaired, episodes where there was somebody pressing on his back while he was on the ground. That prevents the diaphragm from moving and can cause asphyxia, the lack of breathing."

Baden, who spoke from New York, also said there were instances where guards covered the 14-year-old's mouth in order to force an ammonia capsule up his nostril, a tactic guards used to make him more compliant.

"With ammonia in his nose and hands over his mouth . . . he can't breathe, he can't get oxygen," Baden said. "When he leaves on that stretcher, he's already mostly brain dead."

Bay County Medical Examiner Charles Siebert, who conducted the first autopsy, discounted the beating and said Anderson died from sickle cell trait, a common blood disorder among blacks. But Baden disputed that, saying the blood cells probably changed to the sickle shape after he died.

Siebert, though, defended his position in a statement Thursday night.

"My conclusion, based on more than a decade of practice, is that the exertion from exercise triggered Mr. Anderson's sickle cell trait which caused disseminated intravascular coagulation, resulting in hemorrhaging," Siebert wrote. "Complications of sickle cell trait is the cause of death. Because exertion from exercise is a natural activity, I concluded the manner of death to be natural."

Officially, the cause of death is still unknown. Hillsborough County Medical Examiner Vernard Adams ruled out sickle cell trait and other natural causes this week but has not yet settled on an alternative.

Baden's comments came in a hearing of the House Criminal Justice Appropriations Committee, which is trying to decide whether to continue funding the state's four boot camps.

To counter weeks of negative attention, boot camp advocates appeared before the panel Friday.

"I gotta tell you, I love this job. And I care about the kids we work with," said Sgt. Bobby Bowden, who runs the Manatee County camp.

Leo Suarez, 20, warmly described going to the Polk County boot camp two weeks ago to break the news of his marriage.

"They're like my family," Suarez said of the drill instructors he met during a 6-month stay at the Polk County facility in 2003 following drug charges. He has not been arrested since, records show.

Also speaking before the committee were teachers at the facilities and a mother who said the camp changed her son's life.

The comments came as the sheriffs who run the state's four remaining boot camps began talking about how to improve their operations and ongoing tweaking of rules by the state Juvenile Justice Department. But Martin County Sheriff Bob Crowder delivered a stern reminder that it will be wasted effort if the state doesn't fully fund the programs.

"The death of Martin Lee Anderson has hit the juvenile justice system in the state of Florida like a thunderclap. It's drawn our attention," he said. But "there's been a lot of lip service and support and encouragement but it has not been reflected in the state's budget document."

Chris Caballero, second in command at the Juvenile Justice Department, pointed Friday to Gov. Jeb Bush's revised budget putting $1.5-million more into boot camps. Money from the Bay County camp, which closed after Anderson's death, can be spread to those that remain, he noted.

Also Friday, State Democratic chairwoman Karen Thurman called for Hillsborough State Attorney Mark Ober to be taken off the investigation, citing his involvement in the case of Jennifer Porter, the white teacher involved in a hit-and-run accident that left two black children dead in Tampa.

"This goes beyond bad politics. It's bad policy to appoint an investigator involved in one controversial, racially charged case to investigate another so soon afterwards," Thurman said in a statement.