Missouri's Highway Patrol Crime Lab uses employees' subjective opinions, not scientific standards, when determining whether weapons were used in a crime, Public Defender Donald Catlett argued Tuesday afternoon.
Catlett is David Hosier's chief defense lawyer as Hosier, 58, is tried this week for killing Angela and Rodney Gilpin just over four years ago.
Hosier was charged with first-degree murder, armed criminal action, first-degree burglary and unlawful possession of a firearm.
Investigators believe Hosier used a 9 mm Sten submachine gun - designed by the British in World War II, and available today as a build-it-yourself kit - to kill both victims.
That gun was one of more than a dozen found in Hosier's car after it was stopped in Oklahoma about five hours after the murders, Jefferson City police detective Jason Miles testified Tuesday.
"All the weapons inside the vehicle were loaded, except the Sten," Miles said. He and Detective Mark Edwards flew to Tahlequah, Okla., after Hosier's arrest, to collect evidence from the vehicle.
The submachine gun topped the list of weapons used in the murders because officers who went to the apartment building after the Gilpins' bodies were found discovered a number of 9 mm shell casings near the bodies.
The gun immediately was sent to the patrol's lab for testing, and criminalist Todd Garrison testified Tuesday afternoon he determined bullets and shell casings found at the murder scene "could have been fired from the submachine gun."
But, he added, he wasn't able to get better results from the testing, partly because the gun's barrel was so "very smooth and worn" that it left almost no markings on the bullets compared with the ridges and grooves that most weapons produce.
"That was the primary, biggest contributing factor that kept me from making a (better) determination," Garrison told Cole County Prosecutor Mark Richardson.
Catlett challenged Garrison's findings for the number of "inconclusive" results he listed in his report to Jefferson City police and Richardson's staff.
He noted there are national standards and protocols for using fingerprints or DNA evidence in criminal cases.
"In ballistics, it is subjective and based on the determination of human beings?" he asked.
Garrison said: "I would agree."
Computers and digital measurements assist the examiners in their weapons testing, Garrison testified.
But the final reports are "based on the determination of a human being."
Catlett complained the weapons testing generally resulted only in "notations on similarities, not on differences."
While generally agreeing, Garrison said: "If you see differences, you have differences. If you see similarities, you have similarities."
In looking at the submachine gun and bullets found at the scene, compared with bullets fired from the gun at the patrol's testing range, Garrison testified: "I found no differences that were enough to reverse my finding" that the bullets found at the murder scene "could have been fired" by the gun.
Catlett cited a 2006 National Academy of Science study that questioned the accuracy of ballistics tests, noting that "sufficient studies have not been done for reliability."
But, Garrison said, the NAS declined to meet with members of the nation's firearms and toolmark examiners, who wanted to provide answers to the NAS' questions.
The Gilpins' bodies were found lying in the inside doorway to her West High Street apartment about 3:30 a.m. on Sept. 28, 2009 - about the time Angie Gilpin left each morning to drive to Wardsville and open the Bee Line Convenience Store she managed there at 5:30 a.m.
Both victims had been shot in the chest, and Angie Gilpin also was shot in the back of the head.
The medical examiner's testimony is expected this morning, as the trial begins its third day.
Hosier - a former boyfriend whom Angie, 45, had become involved with while separated from her husband, Rodney, 61 - was identified quickly as a suspect in the killings.
Fifteen St. Charles County residents were selected earlier this month as the jury hearing the evidence, with three to be identified as alternates before the jury's deliberations begin.
If the jury convicts on either of the murder charges, Richardson is seeking the death penalty.