Thursday, August 28, 2008
A city crime lab employee left his own DNA on the pistol police say was used to kill an off-duty Baltimore detective, indicating that a recently discovered problem with contamination at the lab may be more widespread than officials originally believed.
Evidence from the murder trial of Brandon Grimes was not among the 12 instances city officials identified last week in which lab employees introduced their own DNA into crime evidence. But lab officials testified yesterday that there are thousands of partial strands of unknown DNA in evidence samples - like the one recovered from the pistol in the Grimes case - that must be checked by hand.
The Grimes case is the first in what city defense attorneys expect will be widespread challenges to DNA evidence processed in the Baltimore lab, whose director was fired last week amid concerns about contamination. In a scene that could play out in other trials, Grimes' attorney attempted to use the problems at the lab to broadly impeach physical evidence usually thought to be unassailable.
Rana Santos, technical chief of the lab's DNA section, said she checked the sample in the Grimes case Monday evening after reports of the contamination appeared in the media and she met with Grimes' defense attorney, Roland Walker. [Mark Godsey]