Orchid Cellmark, a Montgomery County-based laboratory that has analyzed DNA for such high-profile cases as the O.J. Simpson trial and the JonBenet Ramsey murder, has fired an analyst for allegedly falsifying test data - setting off a scramble by defense attorneys to review evidence in the affected cases.
The incident mars an otherwise stellar reputation for Cellmark, a pioneer in the burgeoning field of solving crimes through the analysis of trace genetic material, known as deoxyribonucleic acid, left on evidence.
Cellmark - the world's largest private DNA testing firm, with labs in Germantown; Dallas; Nashville, Tenn.; and Britain - claims that the falsification occurred in only 20 tests, but it is investigating other cases the analyst worked on.
Many of the cases were performed for the Los Angeles Police Department. The alleged tampering has prompted the Los Angeles County public defender's office to begin reviewing all pending cases involving Cellmark.
"What [the employee] did was commit fraud," said Jennifer Friedman, a forensic science coordinator for the Los Angeles County public defender's office. "We now need to figure out ways ... that we and our experts can help to detect these types of problems that we never imagined would exist."
Some of the 20 tests were performed for the FBI. Special Agent Ann Todd, a spokeswoman for the FBI lab at Quantico, Va., would not comment on the matter, and it could not be determined where those cases originated.
Sandi Gibbons, a spokeswoman for the Los Angeles County district attorney's office, said that the cases involving the analyst have not gone to trial, and that there should be no damage to them.
"Cellmark isolated the problem very quickly, they moved on it very quickly," she said. "We don't believe that any cases are going to be ultimately affected by this because all of the cases are being reanalyzed."
The Los Angeles Police Department depends on Cellmark to test DNA in about 250 cases each year, more than half of the department's caseload, said Officer Jason Lee, a department spokesman. In January, Cellmark was awarded a three-year, $2.7 million contract to test new and backlogged cases for the department.
Charlotte Word, the laboratory director for Cellmark in Germantown, would not comment on the company's firing of an employee.
However, in a September letter sent to the Los Angeles Police Department crime laboratory that was obtained by The Sun, Robin W. Cotton, a director of technical forensic science for Cellmark, wrote that the company fired DNA analyst Sarah Blair for "professional misconduct" after discovering that she apparently substituted data for some control samples.
Blair, in a telephone interview yesterday, denied the allegations.
"I explained everything to the company when I left," said Blair, who was based at the Germantown lab. "I'm still sticking to the same story that I'm innocent."
When an analyst, using a computer, finds a DNA match between samples from a crime scene and one from a suspect, additional tests are performed to ensure that the experiment worked properly and is free from contamination.
A positive control test, such as testing a specimen known to contain DNA, should produce a result showing DNA. A negative control test, such as testing water, should show no signs of DNA, said Lawrence Kobilinsky, an associate provost at John Jay College of Criminal Justice in New York.
According to Cotton's letter, when a control test showed an "imperfect" profile and should have been reanalyzed, Blair substituted a control profile with no imperfections.
Cotton wrote that all of the cases affected by the control substitution have been retested, and that the results of the original analysis remained the same. The letter stated that the lab has no information indicating any other analysis performed by Blair was improper, but that the company is continuing to investigate other cases.
Thomas Mauriello, a University of Maryland criminologist, said Cellmark's "stellar" reputation will likely survive the alleged tampering. But the incident opens the door for lawyers to question the lab's credibility.
"If I'm a defense attorney and Cellmark laboratories put my client in jail and got them convicted, certainly I'm going to find out if [Blair] tested the results," he said. "If she was willing to do something not according to the process, what else could she have done or not done?"
The allegations against Blair were publicly revealed in September during a trial in Howard County Circuit Court. Cellmark DNA analyst Kathryn Colombo testified that although Blair substituted control data in 20 instances over nine months, she did not analyze the DNA in the Howard case.
"We don't know why she did it," Colombo said of Blair during the attempted-murder trial of Jerome Clark, 31, of Fulton, who was convicted of first- and second-degree assault. "It seemed to be laziness or expediency."