Prosecutor Michael Cosentino said today that his efforts to convict Ford Motor Co. on charges of criminal recklessness "may be futile" if the court forces him to authenticate documents that Ford turned over to the state under subpoena.

Defense attorney Malcolm Wheeler said that although the automaker had turned over the documents, that does not mean they are authentic.

Ford is charged with three counts of reckless homicide in connection with the deaths of three teen-age girls in a fiery August 1978 crash involving their 1973 Pinto.

The prosecution alleges Ford knew the car's gas tank was prone to explosion during rear-end collisions, but neither fixed the cars nor warned the public.

The case represents the first time a corporation has faced criminal charges for product liability.

Pulaski County Circuit Court Judge Harold Staffeld agreed with Ford lawyers today that even though the automaker produced more than 100 documents under subpoena, they are not necessarily authentic. His ruling seemed to indicate that prosecutors would have to bring in witnesses to testify to the documents' authenticity.

A judge in Detroit blocked an earlier effort to subpoena Ford executives in Michigan.

"We'll have to see if we still have a case," Cosentino said after today's action. "If no documents can go in," the state's efforts "may be futile," he said.

Cosentino called the ruling "crucial" and said that if it stands, "we're not in very good shape at all."

Prosecutors met tonight to study the situation and are to meet with Ford lawyers Wednesday morning to attempt to reach a compromise.

The prosecution attempted to enter into evidence today the May 1978 letter from the National Highway Traffic Safety Administration (NHTSA) that led to Ford's decision a month later to recall 1.5 million Pintos and Mercury Bobcats for fuel tank safety modifications.

The state said the document was offered toshow Ford's prior knowledge about problems with the Pinto.

Earlier, a state police investigator testified that samples removed from various locations of the burned Pinto indicated the presence of hydrocarbon vapors typical of gasoline. The prosecution was attempting to show that because of a body design defect, gasoline flowed into the passenger compartment of the Pinto following the rear-end collision.