Florida ? A teen who died after guards punched and kicked him at a boot camp likely was suffocated during the confrontation and was brain-dead when he was brought to a hospital, a pathologist told lawmakers Friday.

Dr. Michael Baden observed the second autopsy performed on 14-year-old Martin Lee Anderson on Monday in Tampa. He was there on behalf of Anderson’s family, who disputes the original autopsy, which found the boy died of complications of sickle cell trait, a usually benign blood disorder many blacks have.

Baden told the state House Criminal Justice Committee that Anderson did not die of natural causes.

“He can’t breathe, he can’t get oxygen,” he said. “When he leaves on that stretcher, he’s already mostly brain-dead.”