LOS ANGELES (CN) — In the trial of the accused Grim Sleeper serial killer, the prosecution has repeatedly pointed jurors to evidence matching bullets in seven victims with the same .25-caliber semiautomatic handgun.
But as the case edges closer to a conclusion after beginning more than two months ago, defendant Lonnie Franklin Jr.'s attorney Seymour Amster has cast doubt on the DNA evidence used to charge his client as well as firearm examiners' methods for matching bullets.
County prosecutors called several firearms experts to the stand in Los Angeles County Superior Court Judge Kathleen Kennedy's courtroom before resting their case in March. LAPD firearms expert Daniel Rubin testified that examiners can match bullets to a gun by analyzing tool marks on a bullet after a round is fired.
Because the machine tools used to manufacture firearms leave unique marks on the barrel, experts can determine if bullets were fired from the same gun, the jury has heard.
Rubin told jurors that he matched bullets found in victims Debra Jackson, Henrietta Wright, Barbara Ware, Bernita Sparks, Mary Lowe and Alicia Alexander to the same semiautomatic handgun.
The expert said his analysis confirmed that the alleged killer's only verified survivor Enietra Washington had been shot with the same .25 caliber handgun as Wright.
But on Tuesday, defense witness David Lamagna said he believed that law enforcement's methods are unreliable.
Examiners relied on two-dimensional comparison microscopes to analyze the unique tool marks left on bullets. But Lamagna, a forensic scientist and engineer, said he only trusts advanced technologies like 3-D mapping or electron microscopes that allow examiners to look at objects in finer detail.
Amster asked Lamagna if he believed the method used by law enforcement creates conclusions that leave room for doubt.
"Yes. I believe it's mostly subjective in nature at this point," Lamagna said.
He noted that there had not been enough studies done to test the reliability of the tool-mark analysis and said that a forensic ballistics organization, the Association of Firearm and Tool Mark Examiners, has "no mathematical standards" for deciding a match.
Law enforcement lacks specific protocols, he added.
Lamagna said he had traveled to different police departments around the nation and seen varied standards.
"I see different examiners doing their own thing," Lamagna testified.
Lamagna is the owner of American Forensic Technologies, which according to his LinkedIn page provides "forensic review and analysis of evidence in civil and criminal cases" as well as field investigations.
Franklin is accused of killing vulnerable young black women over a period that began in the mid-1980s. His victims were often sex workers, and prosecutors say he prowled the streets during the height of the crack cocaine epidemic — killing seven women during a period that ended in 1988.
Another four murders between 2002 until 2007 have been linked to the Grim Sleeper, who earned the name because of a possible fallow period during the late 1980s and 1990s — though it's believed that the alleged serial killer may have killed many more women.
Judge Kennedy allowed the jury to break early for lunch on Tuesday morning when it became apparent that Lamagna had submitted 380 images of bullet evidence to the defense without notations.
Prosecutor Beth Silverman asked the court to sanction Amster for the oversight. She also asked the Kennedy to instruct the jury on what had happened.
"This is outrageous," Silverman said.
Kennedy chastised Amster for failing to ensure that the images included notations. She told the attorney that while he may not have known that the notes were missing, he should have made sure they were included before they were delivered to the prosecution.
Lamagna said that his notations were in a software program he had used to catalog the evidence. He told the court that it would take him an afternoon to deliver the notations and images to the prosecution.
Testimony was scheduled to continue on Tuesday afternoon after Franklin's defense team told Kennedy that Lamagna could deliver the evidence in the afternoon.
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