Published Thursday, July 7, 2011 | 10:10 a.m.
Updated Thursday, July 7, 2011 | 2:52 p.m.
A DNA mix-up caused by human error that led to the wrongful conviction of a man has prompted Metro Police to reanalyze more than 200 cases handled by a forensic scientist, officials announced Thursday.
Police said an accidental sample switch in Metro’s forensic lab incorrectly identified then-18-year-old Dwayne Jackson as the suspect in a 2001 robbery in the southeast valley. He served nearly four years in prison before his release in 2006.
“To say this error is regrettable would be an understatement,” Sheriff Doug Gillespie said at a news conference Thursday. “It’s unacceptable and not to our standards at the (Metro Police). There are no words I could say that will give back the time Mr. Jackson spent incarcerated.”
The error came to light in November when the California Justice Department contacted Metro to say that an offender in its system matched the DNA profile of forensic evidence collected from a blue, hooded sweatshirt the suspect wore during the robbery. A national DNA database used by law enforcement agencies identified the match.
Police said that information triggered a seven-month process of evaluating the case and re-examining DNA evidence to confirm that a mistake had occurred.
The DNA from the sweatshirt matched Jackson’s cousin, Howard Grissom, who also was considered a suspect immediately after the robbery, authorities said.
The crime occurred Nov. 6, 2001, when a masked robber entered a southeast valley home occupied by a woman and her two daughters, police said. The suspect, who was wearing a blue, hooded sweatshirt and ski mask and carrying a baseball bat, took cash and credit cards from the woman’s purse.
He forced the woman and children into the family’s vehicle and made her drive him to her bank to obtain money, police said. Meanwhile, the woman’s husband and son returned home to find an empty house with doors open and a vehicle missing.
The husband began scouting the neighborhood and found his wife driving back with the man still in the vehicle, police said. The man fled, but police later apprehended two men — Jackson and Grissom — who fit the description that was given, while they were riding bicycles in the neighborhood, police said.
Grissom will remain in a California prison, where he is serving a lengthy sentence for an unrelated crime, police said.
Metro officials said they haven’t personally spoken with Jackson, but they have been handling the situation with his attorneys — a course of action Gillespie said was “appropriate” for the circumstances.
The department and Jackson’s attorneys have reached a settlement, pending final approval by Metro’s fiscal affairs committee, Gillespie said. Police wouldn’t release its terms.
The process of clearing Jackson’s name is under way at the district attorney’s office, Gillespie added.
Linda Krueger, executive director of Metro’s Criminalistics Bureau, said the department’s review determined the DNA sample switch happened sometime during the later stages of technical processing, either during the setup of amplification or the loading of a genetic analyzer.
“This was not a scientific error or a technical error, but a human error,” Gillespie said.
The forensic scientist who handled the case, Terry Cook, has been placed on paid administrative leave while the department conducts an internal investigation, police said. Metro hired Cook in 1983.
Police said it’s unlikely other errors occurred, but the department is evaluating 225 to 250 DNA cases handled by Cook. The cases will be reviewed and submitted for retesting if they include a person and DNA sample from evidence, Krueger said.
“We expect completion of reanalysis (of the cases) within two to three months,” said Assistant Sheriff Ray Flynn, who oversees the department’s criminalistics and internal affairs bureaus. “This is not quick work.”
Metro’s Criminalistics Bureau became accredited in 2003 after meeting a series of requirements and was reaccredited in 2008, Flynn said. When police confirmed the DNA mistake, department officials contacted the accreditation body, the American Society of Crime Lab Directors, to make it aware of the situation.
Attorney David Chesnoff, who is representing Jackson along with his attorney Richard Schonfeld, said Jackson has declined interview requests but is looking forward to a resolution.
“Everybody understands that the imprisonment of someone who is innocent is a terrible event, but Mr. Jackson appreciates the quick response once it was discovered,” Chesnoff said.
Police said they are reviewing their quality assurance standards in the forensic lab.
Police, however, noted that technology changes since 2001 have led to more automation and less reliance on humans when handling DNA samples.
For instance, DNA samples are placed in larger tubes with better labeling and loaded in plate formats, eliminating the need for multiple human transfers, Krueger said.
Since Metro began analyzing DNA in 1997, the department has processed about 8,900 cases, police said. About 44,000 convicted offenders’ DNA samples have been added to the national database, resulting in 1,185 “hits” — or DNA matches — since the department started using the database in 2000.
Krueger said Metro encountered another DNA mistake in 2002, but it was an administrative error converting DNA information to a report format, which did not result in a wrongful conviction.
Gillespie said the department realizes what he described as the “power we have to take away someone else’s freedom,” adding that Metro is trying to rectify the mistakes made.
“When there are (mistakes), I will be standing right here at this podium and admitting them,” he said.