SAN QUENTIN, Calif. -- A case involving a California death row inmate is drawing attention to the reliability of ballistics evidence.

Dennis Lawley, a paranoid schizophrenic, has been on death row at San Quentin since 1989. A jury convicted him of murder for hire in the shooting death earlier that year of parolee Kenneth Stewart in a field just south of Modesto.

Brian Seabourn, the shooter, was convicted of second degree murder.

Investigators found a .357 magnum Ruger in Lawley's cabin and a state ballistics expert concluded the Ruger was the murder weapon. Years later, ATF confirmed the match but said it was a very, very close call.

Lawley's attorney, Scott Kauffman, says his client "is absolutely innocent and was wrongly convicted in 1989 and he deserves a new trial." In fact, Kauffman believes he found new evidence that supports his pursuit for a new trial.

Admitted gunman, Brian Seabourn, told both the prosecution and the defense Lawley had nothing to do with the killing.

Seabourn says he killed Stewart on orders from the Aryan Brotherhood, not Lawley. Seabourn went so far as to draw the defense a map of a Modesto field where he said he buried the real murder weapon, a .357 Smith and Wesson.

Last December, Kauffman found a .357 Smith and Wesson in that field and believes it is the murder weapon.

Unfortunately, 19 years were not kind to the Smith and Wesson. It’s now too old and fragile to fire which means forensic scientists cannot test the new weapon to the old bullet fragments found on Stewart’s body 19 years ago.

When a gun is fired, marks inside its barrel will be imprinted on the outside of the bullet. These so-called tool-marks can be class characteristics which reflect a manufacturer's specification.

Tool-marks also can be smaller, individual characteristics considered unique to a particular gun and can change over time. It was these tool-marks that forensic scientists used to match the Ruger to bullet fragments years ago.

Now, due to time, Lawley's attorney says they "will never be able to definitely prove that the Smith and Wesson fired the bullets that killed Kenny Stewart."

Kauffman is asking the State Supreme Court to order a new trial for Lawley who is now 64 years old.