Kansas City, Mo. ? An autopsy performed on a man who died in police custody showed the death was not a result of the stun gun authorities used to apprehend him, according to the Jackson County medical examiner.

Karl W. Marshall, 32, of Overland Park, Kan., died in January about two hours after police shocked him three times with a stun gun. Marshall died from toxic effects of cocaine abuse, said Jackson County medical examiner Thomas Young.

The autopsy report was released Monday, but prosecutors took it to a grand jury Friday, after community advocates and Marshall’s father questioned whether the Taser shocks proved fatal. The grand jury has not announced its decision.

“True enough he had drugs in his body,” said his father, Nathaniel Marshall. “But he was alive and well when the police approached him. Anyone with drugs in their body, if you Tase them, they could have a heart attack.”

Karl Marshall was taken into custody after police responded to a disturbance call Jan. 28 at an apartment complex. Police said Marshall refused to be handcuffed and was shocked three times in what is called “drive stun” mode, where the shock is delivered as long as the Taser is held against the suspect.

Marshall did not seek medical help and was not taken to a hospital. Police said Marshall was checked twice in his holding cell and was found unconscious during the second check. He was later pronounced dead.

It was the first death after the use of a stun gun in Kansas City.

Young said Marshall did not die of an overdose but instead accumulated damage from habitual cocaine use.