A new way for DNA
It starts with a phone call. The caller is a detective, or perhaps an attorney. The subject is almost always grim: a child molested; an unidentified body found; an old woman murdered; a serial rapist struck again. The call is received with clinical dispassion and centers on basic questions: Was a rape kit taken? How many samples are available? How old is the evidence? Such simple questions set off a chain of events that will likely ease grief, solve mysteries and deliver justice.
Starting this fall, such calls ring through to the third floor of the Industrial Agriculture and Communication Center building at North Dakota State University. Here, smack in the middle of the building like a cell's nucleus, is the nation's newest forensic DNA facility. This is where a small team of scientists use sophisticated equipment to extract the secrets stored in DNA - deoxyribonucleic acid - the miniscule molecule in cells that contains genetic information unique to each individual life form. What they discover will be used in court to help determine innocence or guilt.
The scientists taking those calls will be Berch Henry and Thomas Wahl, veterans of police crime labs who are bringing their expertise to NDSU, where they will focus it on the trickiest of DNA identification cases and on teaching others their craft. This facility will be the first in the country to combine teaching with a functioning forensic DNA lab. Besides taking on cases for criminal investigations, Henry and Wahl will study ways to maximize results from the smallest amounts of DNA evidence. Other NDSU faculty will advance their related research by using the lab's specialized equipment. Government forensic labs will be able to send scientists and technicians to NDSU for training. And doctoral students in biochemistry will be able to add an emphasis in forensic DNA - the first such program in the nation.
The facility also serves as another piece of Sen. Byron Dorgan's vision for a research corridor between Fargo and Grand Forks. Over time, the lab can pull in research grants, train a pool of employees for high-tech and biotechnology industries and raise NDSU's profile.
But the heart of the facility is the ability to analyze DNA for identification purposes in criminal and civil court cases. Henry and Wahl came to NDSU in July 2006 - both leaving jobs with the Las Vegas Metropolitan Police Department - to build a state-of-the-art lab using a $3.5 million grant from the National Institute of Justice. It often takes three to five years to create an operational forensic lab. Henry and Wahl built theirs in two. They converted more than 1,100 square feet of space into four separate lab areas and an office, and they were poised to accept cases as soon as they received final approval on Sept. 24 from the International Standards Organization.
Under the terms of the grant, they must be self-sustaining in three years. While that may be difficult, Henry is optimistic. Unfortunately, he says, crime is a growth industry. Forensic DNA labs around the country battle months-long backlogs that continue to grow as DNA identification becomes the new "smoking gun" in court cases. But unlike backlogged government crime labs, Henry and Wahl will be able to pick their cases. They expect to work routine forensic DNA analysis jobs with deadlines, but their real focus will be on "salvage" cases. They want to work complex cases where little evidence remains and where only the right equipment, technology and experience get results, results that identify a missing loved one, put a rapist or murderer behind bars or even free someone wrongly accused or convicted of a crime.
Building blocks
Henry and Wahl have been on the front lines of forensic DNA analysis since it became part of the modern crime solver's toolbox 20 years ago. They were colleagues at the Las Vegas Metropolitan Police Department - Henry, 59, was the DNA Analysis Unit lab manager and technical leader; Wahl, 54, was a criminalist and DNA analyst at this lab that he also helped create - but both burned out from working with inadequate resources in a city where the population, and crime, were booming.
"We had a backlog as far as you could see and that's just not the ideal way to do things," Henry said. "It doesn't help your analysts to have 20 people beating on them for results. I went through that for years."
Wahl finally retired from the department with no other job on the horizon. Henry was about ready to do the same. Meanwhile, 1,600 miles away at NDSU, Derek Killilea, professor of chemistry and molecular biology, and Robert Sparks, associate professor of chemistry and molecular biology, were laying the foundation for a forensic DNA facility. With active support from Dorgan and NDSU administration, they landed the $3.5 million start-up grant. After three years the facility would need to support itself through casework, consulting revenue and new grants.
Once NDSU had the funding, it needed scientists. Henry was sold, and in turn sold his friend Wahl on the unique prospect of building a lab from scratch on a university campus with sufficient funding and the autonomy to choose their cases. Henry and Wahl designed the lab to fill a needed niche in forensic DNA analysis - analysis of complex cases with very little left to test; old, degraded samples; or mixed samples.
As program and laboratory director, Henry runs the facility, manages the budget, and finds new customers and grants. Wahl, as senior forensic DNA analyst, supervises the hands-on casework and manages the facility's quality assurance program. Like the two nucleotide strands that make up the double helix of DNA, they complement each other. They know each other's strengths and divide up the work almost without talking.
When Henry talks to you, his focus is complete. Yet he seems relaxed as he leans back in his chair. His left arm drapes over the top of his head while he scratches the opposite ear. Occasionally he removes his square, wire-rim glasses and spins them around by the stem. With his fair hair, pale blue eyes, short white beard and burly build, it's easy to imagine him on a Viking ship. The southern influence from his hometown, Little Rock, Ark., can still be heard, particularly when he uses phrases like "drum up some business" and "bang for the buck."
Wahl talks with his chair swiveled to the side while speaking, one arm on the armrest, the other on the table. Comb grooves are visible in his silver hair, and his white moustache and goatee are trim. The top three buttons of his shirt hang open, and he seems relaxed even while describing the odor of crime scenes. Almost the only time his slightly raspy voice shows irritation is when he recounts the story of a suspect convicted on flawed bite mark testimony. (The man was released 10 years later when DNA evidence matched a known, incarcerated rapist who then confessed.) Forensic DNA analysts are a unique breed. They have to be the stereotypical detail oriented, analytical lab geeks. At the same time, they need the stomach to work with grisly case evidence, the verbal skill to explain their results to juries and the confidence to stand behind their work when lawyers try to bend or discredit their testimony.
"Court is like theater," Wahl says. "You go to court and you're on stage so to speak. If I know it's a high profile case and the defendant has a very good attorney, I know I'm probably in for a long day on the stand."
Both Henry and Wahl exhibit a laid-back self-assurance gained from decades in the field. Both of them talk about graphic crimes the way a mechanic might talk about a car. They focus on the evidence, not the emotion, of crimes. For example, while recounting his testimony on a rape case, Henry says, "All I can tell you is that sperm was detected in her vagina. How it got there? Hey man, I don't know. I wasn't there."
HenryWahl
Henry's interest in science was solidified by his sixth grade teacher, Mrs. Barton, who borrowed a projection microscope so the students could examine pond water. Watching the floating paramecia and amoebae led Henry to a love of the microscopic. He went on to earn degrees in microbiology and was teaching genetics at the University of Nevada School of Medicine in Reno in the late 1980s when two students told him they wanted to start a DNA laboratory for the Washoe County Sheriff's Department. He built their DNA facility, the first lab west of the Rockies doing casework to his knowledge. In 1998, Henry became lab manager of the DNA Analysis Unit for the Las Vegas Metropolitan Police, where he met Wahl. But the lab was understaffed and overworked. Henry worried about things dropping through the cracks. "It's frustrating because you really want to do a good job, but you can only do so much," Henry says. Then the NDSU opportunity knocked.
Like Henry, an early experience with a microscope and pond water drew Wahl into the sciences while he was growing up in west central Wisconsin. He fell into the forensic field by applying for a crime lab training position at the Wisconsin State Department of Justice Regional Crime Lab in Milwaukee in 1980. Wahl has since testified in more than 300 cases and is court-qualified as an expert witness in 21 U.S. and two Canadian jurisdictions. He was still working with the Las Vegas Metropolitan Police when he met the producer who wanted to set a TV drama in a crime lab. Wahl remembers not thinking much of it as the "struggling" producer went through his lab. His reaction later, when "CSI: Crime Scene Investigation" hit it big: "Lucky guy."
Along with Henry and Wahl are two rookie analysts, NDSU graduates Jack Foster and Megan Palmer. For the past year, Palmer and Foster have been training in the exacting work of forensic DNA analysis and how to hold up under intense pressure in court. It's Palmer and Foster who have spent a vast majority of their time in the lab validating every extraction and analysis technique and, once cases start coming in, it's Palmer and Foster who will perform most of the hands-on casework analysis.
Jack Foster, 31, grew up in rural North Dakota, and his small-farm work ethic serves him well in DNA analysis. He's the type of person to keep working on a problem until he figures it out - a nice trait to have when reading 2,000-page instruction manuals to troubleshoot glitches. Before joining the DNA lab, Foster worked three years at the NDSU Veterinary Diagnostic Laboratory where he performed diagnostic tests for animal diseases like West Nile virus and anthrax.
Megan Palmer, 24, is the most soft-spoken of the quartet. She's a Type-A personality who prefers to keep busy. To that end, she also is working toward a master's degree in biochemistry. She had planned to work in mortuary science, but found she wasn't comfortable working with grieving families. She shifted to forensic pathology and eventually into forensic DNA analysis.
When Foster met Henry and Wahl, he was impressed by their straightforward manners. They let him know the lab was funded by grant money with no guarantees beyond that. Palmer was working on her biotechnology thesis the summer of 2006, working out of an office across the hall from the start-up lab. She met Henry and applied for a job.
For his part, Henry says both Foster and Palmer displayed the self-confidence he was looking for in lab analysts, yet they knew when to be quiet and listen.
"You want people to keep their mouths shut and learn, but when the time comes for them to step to the plate they need to do that," Henry said.
working cases
Detectives interview witnesses, victims and suspects. Crime scene investigators hunt and gather evidence. DNA analysts analyze DNA evidence. That's it. They don't mix duties. So forget the dramatic TV scenes of lab scientists out in the field confronting suspects.
"You would never see that," Wahl says. "It would be highly unusual. We are in a specialized world. Very few people can grasp everything about a certain field."
To clear misconceptions, Henry and Wahl detailed the way forensic DNA analysis really works. While there is no typical case, this is the basic chain of events once Henry picks up that ringing phone.
Henry and Wahl first determine if NDSU has the capability to do the analysis needed in a particular case. They need to know what evidence is available and what questions the client needs answered. The goal is to determine what evidence to analyze for probative value - evidence that will give them the best results for use in court. For example, in the case of a sexual assault, they might just need to analyze the rape kit swab and reference samples from the victim and suspect. A homicide might have 50 to 100 pieces of evidence to consider for analysis. Henry's biggest case involved a suspected serial killer in Reno. Almost 1,000 items had been collected as evidence; he ended up analyzing 10.
Choosing what to test keeps time and expenses down. A straightforward three-item case from start to finish costs about $3,000. The more samples, the higher the bill.
The evidence arrives, typically via Federal Express, and is then examined, documented and evaluated to determine whether DNA analysis will work. For complex cases, this is where the NDSU facility plans to fill its niche in DNA analysis.
The showpiece of the lab is a Zeiss P.A.L.M. MicroBeam Laser Catapult Microscope, a large white machine that takes up half a room. The Zeiss LCM will make possible research and casework analysis that other labs can't perform. Such equipment costs too much for government labs that wouldn't use it enough to justify the $250,000 price tag. This specialized microscope allows analysts to capture cells from mixed samples containing cells from two or more donors. Because DNA testing may destroy samples, the Zeiss LCM can provide the edge needed in cases where little evidence is left. Only a handful of labs in the country have this technology; one successful analysis of a high-profile case could secure the NDSU facility's reputation.
Today Foster is using the Zeiss LCM to cut out mouse lung cells as part of a research project for assistant professor of microbiology, Jane Schuh. (See the last issue of NDSU Magazine for more.) Seated at the Zeiss in a polo shirt and jeans, Foster clicks a button and the computer monitor projects an image of the cell wall structure in electric blue. It resembles a topographic map, with large open white spaces like lakes surrounded by numerous blue lines. The white spaces are lung pockets, the blue lines, cell walls.
Foster hands control over to Palmer, who uses the cursor to trace around the desired cells. Then the Zeiss LCM shows its true power. The laser cuts along the path Palmer laid out. Once done, the Zeiss LCM shoots the laser at the cells to create a small pocket of pressurized air. The cells are popped, catapult-like, into one of the eight tiny test tubes attached to the machine's automated tray.
Blink and you'll miss it on the monitor. You'll miss it anyway. One nano-second, the cells are there; the next, there's a hole where they used to be.
Palmer and Foster now move on to the next evidence-related demonstration - the "fabric of shame." Dressed in a lab coat and latex gloves, a pair of yellow goggles perched atop her auburn braids, Palmer spreads out a quilt composed of 42 different fabric squares. Each of the squares - denim, silk, spandex, nylon, wool, polyester, cotton, and various blends - is stained with various body fluids. Some of the stains are easy to spot. Others are not
Next to her, a black, rectangular box about one foot long drones loudly as three fans keep the unseen halogen light from overheating. Palmer attaches a metal snakelike hose to one end of the box. On the other end of the hose she hooks on a light-filtering device.
Foster turns off the overhead florescent lights and Palmer passes the halogen alternate light source over the quilt. To the naked eye the light is a blinding bright blue. With a pair of orange-tinted goggles on, the light from the hose looks dim and yellow. Certain stains show up under the light.
"See how that is all wicked out?" Palmer asks, indicating a stain that has spread over one quarter of its patch of fabric. "Can you see the two different stains? On silk, you can't see that stain with the naked eye."
We finish looking at the fabric and enter the lab's largest room where DNA is extracted from evidence. For those whose only exposure to DNA labs is through television shows, this room is something of a letdown. No floor-to-ceiling windows to let in golden Miami sunsets through expressive blinds. No detectives removing sunglasses to mumble quips about finding the truth. You wouldn't be able to hear them anyway over the low level hum of the air vents, florescent lights, refrigerators and computer server. Palmer and Foster don't even notice the noise anymore.
Two long slabs of slate reach out from one side of the room. Each slab is filled with computers, extraction machines and measuring boards, one of which has a high-definition stereomicroscope mounted over it to catch details of small items - such as a speck of blood in a diamond ring's setting. Foster shows some test photos on the monitor. A small piece of blood-stained fabric shows up so clearly that it is easy to see the weave. One square centimeter (about the size of George Washington's head on a quarter) of the stained fabric provided enough DNA to analyze 50 times over.
The Zeiss LCM, the halogen alternate light source, and the stereomicroscope help examine and select evidence, extract DNA and separate mixed samples. Once they have the DNA in hand, they quantify it. They need to know exactly how much DNA they recovered so they can add the right amount to the biochemical process known as PCR - polymerase chain reaction. This process uses a mixture of primers, nucleotides and DNA polymerase (a bacterial enzyme). Too much or too little DNA added to the PCR mix can ruin results.
The DNA and PCR mix is heated, which causes the two strands that make up DNA to break apart. As the solution cools, the primers (which are tiny pieces of DNA) get to work. Bits of primer attach to the now single strands of DNA only in the region of interest. The enzymes build on the primer to create two new strands of DNA. The heating and cooling is done over and over, up to 30 times. Like a molecular Xerox, soon there are millions of copies of tiny, specific parts of the original DNA strands. These small pieces of DNA are compared to the DNA of the known suspects and victims.
Results come in one of three forms - DNA match, non-match or inconclusive.
If the samples match, the analyst puts a statistical weight on it to help juries understand the probability of finding someone else with the same DNA profile by chance. The odds can be astronomical, but for simplicity's sake, the NDSU analysts typically make an identity statement when the chance of finding another person with the same DNA profile is 1 in 700 billion, 100 times the world's estimated population. This doesn't include cases of identical twins, who have the same DNA profile.
In other cases, the samples may not match. More than 200 convicted felons have been exonerated by DNA evidence since Gary Dotson became the first in the United States to have his rape and kidnapping conviction overturned in 1989. Exonerations are highly visible in the media, yet less reported are the innumerable instances where DNA analysis keeps cases from going to court because it proves the accused likely isn't guilty.
Television shows may give the impression that DNA is always clear-cut, but it isn't. Inconclusive results also happen. Mixed DNA samples with cells from two donors can provide ambiguous results. Get 10 analysts to look at mixture data, and you can get 10 different interpretations. Determining a sound interpretation is the hardest part of the job, Henry says. However, with the Zeiss LCM, the NDSU facility will be able to better separate cell mixtures to get a profile from one donor - making interpretation easier and less ambiguous.
Whether the DNA is a match, non-match or inconclusive, the analyst must testify as an expert witness if the case goes to trial. This can be tricky since expert witnesses are allowed to provide opinions. But Wahl and Henry believe in being neutral, objective scientists, a belief they sometimes have to remind themselves to hold.
"You got some two-year-old kid that was sexually assaulted, you know that's going to piss you off," Henry says. "You can't show that."
They go toe-to-toe with lawyers who try to push their conclusions and opinion one way or the other, but they stick to what the evidence shows. What they do know is DNA: DNA they know was at a crime scene; DNA they know matched or did not match a person. Forensic DNA analysts tie the suspect to the crime scene. Beyond that, why the suspect was there and who did what, they can't say. That's for the jury to decide.
"You don't know what really happened," Henry said "And I've been fooled. We both have. I've been fooled enough times to know better."
-- J. Hagen
