A nationalist killed in a shootout with the FBI did not die immediately, an autopsy showed.

SAN JUAN - (AP) -- An autopsy indicated a Puerto Rican nationalist killed in a shootout with FBI agents did not die immediately, a justice official said Sunday, fueling criticism of the FBI for waiting almost 24 hours to enter the farmhouse where the fugitive lay wounded.

Filiberto Ojeda Ríos, 72, who was wanted for a 1983 robbery of an armored truck in Connecticut, fired on agents who came to arrest him Friday at a farmhouse in Hormigueros, the FBI said Saturday. An agent was wounded, the bureau said.

The agents waited until the next day to enter the farmhouse because they were unsure if explosives were inside, Luis Fraticelli, the special agent in charge of the FBI for Puerto Rico, said Saturday.

The agents, who had been staking out the farmhouse for four days, waited for a team trained in detecting explosives to arrive from Virginia, he said.

Ojeda Ríos died from a bullet wound to his shoulder that went out through the middle of his back, piercing his lung, according to an autopsy, said Justice Secretary Roberto Sánchez Ramos.

Results from the autopsy late Saturday did not determine a time of death.

Sánchez Ramos criticized the FBI for refusing to allow four local prosecutors to enter the farmhouse after the shootout.

''The information we have is that if Mr. Ojeda had received immediate medical attention after being shot, he probably would have survived,'' he said.

FBI spokesman Louis Feliciano declined to comment Sunday.

Independence activists have accused the FBI of assassinating Ojeda Ríos.

''They did not come to arrest Filiberto Ojeda, they came to kill him,'' said Héctor Pesquera, president of the Hostosiano independence movement.