Flagstaff criminologists help to solve local cases
Becky Love-Holt looks through a microscope at a "rape kit" from Tuba City.
Bob Burris, regional crime lab manager, said the Flagstaff lab "has experienced a tremendous increase in the number of requests." He added that the lab processed about 100 DNA requests last year.
"We don't have the resources to do DNA tests for every sample that comes through the door," he said.
The lab has a staff of 16 people with varied expertise including DNA, drug, arson, fingerprint and weapon analysis.
Becky Love-Holt works in the Serology/DNA department. Her job is to determine if it is possible to extract DNA from a blood or cellular sample found at a crime scene and then try to match the sample to the suspect.
Technological advances in the past two years have made her job faster but has also provided a way to find new leads in old cases, creating a backlog of projects.
"A lot of detectives are looking through old cases," she said. "We're a couple of weeks back-logged. The DNA is piling up."
Only a few years ago, criminologists required a large sample for DNA testing. The new technology allows her to "reproduce DNA the same way the body does." That means Love-Holt needs only a single cell to complete an accurate test.
She said she removes the DNA from the nucleus of a cell by boiling the cell to break the cell wall –a process that takes about an hour. She said she also can use soap to break the cell in contaminated samples. That process takes about three hours. She said if the sample is too small she can create more DNA by heating the strand and causing it to split, and then adding a bacteria found in a hot spring acts as a "copy machine" for the separate parts of the DNA strand.
"It (the bacteria) is able to withstand the heat that is used to split the strand … and attaches to the DNA, and it's what makes the duplicate," she said.
She said the process is automated and that after the equipment repeats the process 28 times there is enough DNA to test.
The technique allows Love-Holt to verify, among other things, whether or not a person has handled a suspected murder weapon.
Polk said being able to rely on a smaller sample for DNA evidence has made prosecution more effective.
"Oftentimes we'll have a homicide and no witness and the evidence is blood evidence," she said, adding that sometimes that is enough to link a suspect to a crime.
The process is time consuming because it is sensitive and requires constant control checks, but "if all goes well we give an oral (report) in a week," she said.
Love-Holt said she does not test every sample that investigators bring her. She added that even though there are many cases from the past that investigators are asking her to test, she gives top priority to cases that "have court dates or if the prosecutor is afraid the suspect will flee."
Love-Holt is not the only criminologist who faces a surplus of cases. Burris said that 65 percent of the 3,365 cases they handled in 2001 dealt with identifying drugs.
Mary Hutchinson and Philip Jackson work in the part of the facility that analyzes drugs. Hutchinson said identifying drugs seized from a crime scene is a process that can take a few minutes or a whole day.
"It depends on the items," she said.
John Hoang handles many of the investigations involving arson. He looks for fire accelerants such as gasoline in debris found after fires. He said it takes about an hour to find an existing accelerant in every sample. He added that he worked on 31 arson cases in 2001 and that the cases usually have many samples requiring analysis.
Latent print examiner Dick Erfert and criminologist Richard Maclean identify people, dead or alive, by studying fingerprints. He said investigators can use fingerprints to determine whether or not a person was at a crime scene if there is a usable fingerprint found on a permanent object at the scene.
"You can get a latent (invisible) print from everything but oil and water," Erfert said.
He added that they are also able to identify the remains of dead bodies sometimes.
"You can get ridge details from the skin from bones," he said, adding that that process is a little more time consuming than using black powder to dust for prints.
The latent print department is also backlogged. Erfert said they have a backlog of 50 to 60 cases.
"We always have a backlog," he said. "There's never been a time that we've not had a backlog."
Criminologist Terry Weaver helps to identify weapons and tools that investigators believe criminals used. He said he can determine if a suspect used a specific gun or even a specific bolt cutter to commit a crime.
He said there are several ways to make gun identifications because the barrels and bores each have unique markings inadvertently made during production. He can match the scraping patterns left on ammunition to the gun that it was in. He said he usually does this by firing the weapon and comparing the bullet he fired to the one in evidence. He added that he uses a similar technique to identify other objects, such as bolt cutters.
While the analysis may sound relatively simple, complexities do arise. Recovered bullets are often damaged. He said that sometimes all he has to work with is a fragment of the bullet.
"I've looked at a single bullet for the better part of a month," he said. "Science is empirical. You have to look at what you've got."
The criminologists do work with what they've got but it is a lot of work. Polk said that despite hefty work assignments and past cases finding their way back into the system, the criminologists at the Flagstaff crime lab do a good job of prioritizing their work so that they complete the most pressing projects first.
"It definitely affects the amount of time it takes to prepare for trial," she said, "but the DPS crime lab has been wonderful at prioritizing. We've never had to dismiss a case because the testing wasn't complete."
Public Defender Dan DeRienzo said that having an extra DPS crime lab would not affect the Public Defenders Office.
"They're (DPS) working for the state," he said. "If we want to do DNA testing or any other testing, it has to go to a private agency. I don't know that the locality makes a big difference."
Prescott Police Sgt. Mike Kabbel said that having an additional crime lab in the Prescott area would make things more efficient.
"It would help speed up the process if there were more people," he said.
He also said it would be more convenient for investigators if an officer did not have to take the property and evidence removed from a crime scene to Flagstaff.
Burris agreed that extra staff does make the job easier, but added that the staff has nearly doubled since the Flagstaff crime lab opened in 1995 and consequently "we're pretty crowded now."
Contact C. Murphy Hébert at firstname.lastname@example.org