Culling Evidence Against Killers and Rapists: A Day At Westchester's Crime Lab

Westchester's crime lab is a serious place. Staring at my clinical surroundings and the fishbowl of scientists working diligently behind a glassed-off area, I started fidgeting as I waited in the lobby.

Straighten up, I thought, spit your gum out, and think scientific thoughts!

After signing my name in the register and greeting the receptionist, the only thing left to do was look through the plexiglass at scientists in goggles and white lab coats walking back and forth from one piece of high-tech machinery to another, running various tests on what I imagined to be fragments of shattered collarbone.

After a minute I heard high-heels clicking down the hallway and turned to see Dr. Betsy Spratt, Director of Forensic Toxicology, buzz into the room with her key-card. I was about to get schooled in the science of criminology.

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The Department of Laboratories and Research, aka the crime lab, is hidden away among the many buildings that comprise the Valhalla Medical Center. It's one of four similar laboratories where multiple divisions are housed under the same roof. Its neighbors are the Yonkers Detective Division and the County Police Department and Ballistics. But the crime lab is truly full service.

Consider a death investigation -- the body goes to the Division of Forensic Toxicology for drug testing, then to the medical examiner's office for an autopsy, and finally to the morgue. Since they're all housed in the same complex in Westchester, it makes life easier for the technicians, doctors and investigators who work those cases.

Also on site are the divisions of Microbiology and Environmental Laboratories. They're responsible for testing beach water every morning during the summer, making sure our tap water isn't toxic and taking soil samples from across Westchester. 

But the labs can also test for chemical or biological contamination when court-ordered, which helps to expedite results. In other counties, that kind of testing simply doesn't happen in-house, and results can take weeks or months to come back from a state police lab in Albany.

Although each division operates in separate, self-contained silos, they all work together toward uncovering the fundamental facts of a case—the only caveat is no one is allowed to know the subject's names or to take a personal interest in the cases because that would compromise objectivity. Instead, numbers are used, hence the tag with the string tied around the big toe commonly seen in movies.

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Many recall July 26, 2009, when Diane Schuler, 36, drove the wrong way on the Taconic Parkway and collided into an SUV, killingall passengers in both cars except for her five-year-old son. The toxicology on Schuler's body was done at the crime lab. The report was crucial in deeming the case a homicide, revealing Schuler's blood-alcohol level was more than twice the legal limit and finding a high concentration of THC, an active ingredient in marijuana, in her system.

The crime lab was also instrumental in helping to convict a Level 3 (high risk) sex offender who raped a 12-year-old girl from Brooklyn in an Ardsley hotel room in 2007. William Davis, 46, was found guilty after the crime lab was able to find small particles of foam from Davis' car seat on the girl's clothing. He was sentenced to 25 years to life in prison for four counts of predatory sexual assault and second-degree kidnapping, among other charges.

In both scenarios, the prosecution relied heavily on trace evidence to press their case -- evidence like DNA, particles of fabric, small pieces of thread, paint chips, hair follicles, and even shoe-prints. No matter how seemingly insignificant the biological footprint, most evidence left at a crime scene can easily be traced. There's no job too small when you have one piece of specialized, top-of-the-line equipment to check for gun-shot residue and a different multi-million-dollar machine to check specifically for something else.

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Nowadays, scientists are able to go back in time to solve cases previously tabled or deemed inconclusive. The technology that allows them to do that is Short Tandem Repeat (STR), a method for reading DNA that was popularized a decade ago as an alternative to the older, more time-intensive method called Restriction Fragment Length Polymorphism (RFLP). STR allows scientists at the crime lab to open their Cold Case Initiative, 'cold' referring to cuttings from evidence that had been frozen with the purpose of re-examination.

Elayne Schwartz, the crime lab's supervisor of forensic biology, recounted a murder in Yonkers where a 14-year-old was sexually assaulted and suffocated while she was out fetching milk. At the time, there wasn't enough evidence to convict anyone. But when forensics experts compared the DNA in that case to samples from murders in 1988 and 1990, they found it matched Patrick Baxter, a then-31-year-old former Yonkers man who was already serving time in state prison for unrelated crimes.

Baxter would have gotten parole in another year. Instead, thanks to the Short Tandem Repeat method of reading DNA, he was found guilty in 2002 and was sentenced to a minimum of 75 years in prison.

STR technology relies mostly on buccal swabs, basically Q-tips that swab the buccal cells on the inside of your cheek. Buccal swabs are used in STR because they're less susceptible to contamination. A new law in New York state will require minor offenders to submit to submit to swabs, which will be added to CODIS (Combined DNA Index System), the state database, for a period of at least 10 years.

The techs at Westchester's crime lab don't talk politics or civil liberties, and declined to comment on the implications of the law -- or similar laws that would expand DNA testing. They're content to stick to their microscopes and machinery.

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There remain some stubborn misconceptions about crime labs. It's not like CSI, where techs can search a crime scene for clues, question the suspects, and solve the crime, all within the space of an hour. 

"Everything is correct, except for the time factor," said Bharat Lakhkar, assistant director of forensic science. "And of course, we leave the investigation to the police."

Even so, it must be fun to work at crime lab as an employee. It doesn't matter that it may not be as glamorous as on TV. More college students are interested in pursuing forensics, the CSI effect cited by employees like Keith Mancini, who works as forensic photographer. 

"We've been getting more requests for internships" said Mancini, "It must be that schools are responding to the demand for programs in forensic science."

Most view Westchester as a leafy suburb, but any county of a million residents will see its share of murders, robberies, assaults and rapes. 

The lab processes 1,700 submissions for drug-testing and toxicology per year, 200 pieces of trace evidence, and 900 pieces of DNA -- in all, almost 3,000 requests each year.

Brian Rothenberg is a forensic science specialist and member of the crime scene team, which visits crimes scenes when evidence can't be brought to the lab. 

"We still get the cases where you just say, 'Whoa" said Rothenberg, "Crimes do happen here."