Baltimore crime analysts have been contaminating evidence with their own DNA - a revelation that led to the dismissal this week of the city Police Department's crime lab director and prompted questions yesterday from defense attorneys and forensic experts about the professionalism of the state's biggest and busiest crime lab.
Edgar Koch, who had been the city lab's director for the past decade, was fired Tuesday because of the DNA contamination and other "operational issues," said police spokesman Sterling Clifford.
He declined to elaborate on the other issues and said no one else was terminated.
City officials said the employee contamination did not lead to anyone being falsely accused of a crime, and they played down its importance.
But Baltimore's top public defender called the findings "atrocious" and Baltimore State's Attorney Patricia C. Jessamy said she has asked her senior staff to review the potential impact on open and closed cases.
By introducing their own DNA into crime evidence, lab employees may have created more work for detectives and made prosecutions harder, as the presence of unknown DNA can leave the impression of a phantom suspect, experts said.
Defense attorneys said any flaws in the city's handling of DNA could raise broader questions about evidence that is generally considered infallible. As testing becomes more sophisticated and new standards for labs emerge, cities across the country, including Houston and Seattle, have been discovering contamination issues that in some cases led to convictions being overturned.
"There are some concerns," Mayor Sheila Dixon said. "We don't have the details yet to know if these cases are in jeopardy, so I can't speak on that publicly yet."
The problem in Baltimore came to light when a new DNA supervisor in the lab, Rana Santos, began entering employee DNA samples into a database and comparing them against "unknown" genetic profiles found in evidence from crime scenes.
Santos' work has revealed about a dozen instances out of 2,500 in which a previously unknown genetic profile turned out to be that of a lab employee, Clifford said. The analysis is continuing, he said, with more employees' DNA being entered into the database and more unknown samples being re-examined.
Reached at home yesterday, Koch, a former Anne Arundel County police officer who developed the forensics lab there, said supervisors had mistakenly believed since 2005 that the lab staff's DNA samples had been entered into the database when they had in fact been sitting on a shelf.
