Crime Labs: The next contamination control market?
By Lisa A. Coleman
Washington, D.C.–One thing the O.J. Simpson trial has brought into the limelight is the importance of contamination control. Collecting evidence requires caution, the correct packaging, and contamination control. One submicron of dirt, blood or dust can ruin or distort evidence. Crime labs often rely on the same principle that biotech labs do: keep contamination out.
Says Linda Sherlock Reich, Forensic Scientist II for the Suffolk county crime lab in New York, “It would be pointless doing what we`re doing if we had a contamination problem.” Crime labs work to associate evidence from a crime scene with a person, a hair, a fiber or a body fluid. “There`s always an association and you want to avoid contamination at all costs.”
At a crime scene, police collect evidence and place it in paper or sometimes plastic bags. When it`s admitted to the crime lab, analysts examine all the evidence in a “scrapping room,” where trace evidence is collected. Clothes are checked for hairs, blood stains or anything that would link a suspect to the victim. The victim and the suspect`s evidence are kept separate. Any stains on clothing are cut out and sometimes refrigerated or frozen. Controlling the environment in which the evidence is tested is crucial to keep the evidence as free of non-crime scene related particulate as possible.
The New York State Police are building a new state-of-the-art $25 million crime lab with 100,000 ft2 of lab space and cleanrooms with laminar air flow. The crime lab is one of many new labs being built across the country. Arizona, Florida and Virginia are also building new labs and the trend will increase as new equipment and techniques spur better lab environments, more space and more staff.
At the forefront of New York`s crime lab design was a concern for the safety of the staff. “A lot of the work we do is biological in nature,” says Bob Horn, Director, New York State Police Crime Labs. “Handling that type of product, like evidence from a homicide such as bloody clothing, you not only have to ensure the safety of your staff but you also have to protect the items from contamination and cross-contamination,” he adds.
That`s where cleanrooms help. The new crime lab will have six cleanrooms in which one case`s evidence, item by item, can be worked on and then cleaned up for the next case. The ventilation system is a one-pass, laminar-flow-type system where the air exits the room through the floor and is never recirculated. “The cleanrooms were created for people to go in and work on a homicide case. The analyst who`s working on the case and the evidence are protected,” says Horn. Some of the rooms can be used for highly infectious materials and the cleanrooms serve as a anteroom or foyer for other rooms where evidence will be examined.
The New York lab is being built for two main reasons, says Horn. First, forensic science is at a different plateau than where it once was. New technologies require new equipment as the type of work crime lab analysts expands dramatically. Since 1987, Horn reports that his lab is handling 10,000 more cases. Second, a safe work environment for the crime lab staff also prompted the new lab. Additional safety concerns caused more fume hoods and biological safety hoods to be added for the staff. Every analyst that needs to work in a hood will have one available.
Besides housing the crime lab, the building will encompass all the forensic services, such as an autopsy room, an automotive lab for crime scene searches of vehicles, a computer crimes unit, and the Homicide Assessment Lead Tracking (HALT) program for researching serial crimes. The building is slated for completion in April and will be in use by late June 1996.
The Federal Bureau of Investigation`s crime lab is one of the largest in the country. The FBI crime lab is divided into five sections with each section broken down into several units. The scientific analysis section has many charters including a chemistry and toxicology unit that studies biological tissues, poisons, arson materials, and drugs. Another unit studies DNA, firearms, hair and fibers. A fingerprints section studies latent prints found on objects and uses light sources, such as lasers to find prints. The special projects unit performs video imaging and enhancement, facial reconstruction and composite sketches. The other units include a structural design unit and of course, forensics. “In most evidence handling,” says FBI Spokesman Paul Bresson, “it`s not necessary to have special filtration but there are some pieces of evidence that require certain air systems, for example blood is usually stored in a refrigerator to keep it fresh.” Everyone in the scientific analysis section wears gloves, nose and mouth protection and sometimes specially fitted OSHA-regulated masks to keep out toxic fumes. n