COLUMBUS, Miss. (AP) - When Austin Shepherd graduated from high school in 1997, his native city of Columbus was amid reeling from a string of violent murders that had already claimed two elderly victims.
By the end of the next year, three were added to that tally. Though the cases remained unsolved for the next two decades, Shepherd’s key contribution led to a break in one of the cases and brought a suspect into custody. For the forensic scientist who is director of the Columbus Crime Lab, it was the first step toward his goal to solve those five murders he had set for himself years before - a goal that drew him back home in 2004 from his former position with the state crime lab.
U.S. marshals recently arrested 52-year-old David Murray in Jackson for the capital murder of Mack Fowler - a 71-year-old stabbed to death in his home in July 1996. Authorities matched a DNA sample Shepherd had entered in 2006 to the Federal Bureau of Investigation’s Combined DNA Index System (CODIS) from the Fowler case with a swab of Murray Jackson police collected from his October 2016 aggravated assault arrest.
The moment was a personal triumph for Shepherd, who said he did “a lot of fist-bumping” and “maybe a little dancing” when he found out DNA evidence produced a match in the nearly 21-year-old case.
“I think all the way back to 1997 when I was graduating high school thinking how great it would be to be able to help out, and here we are in 2017 and it’s kind of like we’ve come full-circle,” he said. “It’s, for me, a really fulfilling and rewarding experience and I know it was for a lot of people.
Still, Shepherd said, as a forensic scientist, his primary objective with any case is to produce good science. Murray’s arrest, fulfilling as it may be for Shepherd and a city that’s wondered for 20 years if Fowler’s killer would ever be caught, may prove to be a testament to the strength of DNA as a forensic science tool.
Shepherd said DNA analysis - as with any other type of forensic analysis -always starts with collection.
He said it’s best to collect a whole piece of evidence whenever possible, but that’s not always doable. It isn’t reasonable, for example, to expect a police department to have space to store a refrigerator with blood splatter on it. In those instances, investigators collect samples for analysis.
“Any time you have a personal crime or a violent crime, DNA is going to be a viable option,” Shepherd said. “In those, we at least look for it 90 percent of the time. Those other 10 (percent), we still have evidence that could have DNA on it, but the fact that DNA from the bad guy is there may not offer us anything as far as the case goes.”
DNA’s usefulness is circumstantial, Shepherd said. For example, he said a sample taken from a convenience store countertop in an armed robbery investigation might not say anything more than a person was one of many who’d been at the store at some point.
“It’s always good to try for it, but what I’m saying is it’s much like fingerprints- if the person is supposed to be there or they had the item in their possession, then you would expect to have their DNA on it,” he said.
Still, Shepherd said DNA is particularly useful for sexual assaults, homicides, some armed robberies and home invasions. He said it all depends on the circumstances.
“Even sometimes in armed robberies at stores and stuff like that, depending on where it’s at- your DNA could exist here and that would be fine,” he said. “But maybe behind the counter on the safe handle — your DNA probably shouldn’t be there.”
Deedra Hughes, DNA technical leader and CODIS administrator for the Mississippi Crime Lab in Pearl, said DNA is also collected from all convicted felons and, more recently, anyone arrested for a felony offense or violent crime. Those samples are entered into the state and national databases.
Murray, who former police Chief Pete Bowen said was never considered as a suspect after Fowler’s death, might never have been found if for two matched DNA samples.
“DNA is very powerful data,” Shepherd said. “It’s very powerful evidence.”
The CODIS system, created in 1998, contains samples from State DNA Index System databases and the National DNA Index System. In Mississippi, according to the FBI’s website, the system had aided 527 investigations as of April.
Once a sample is collected, it’s sent off for analysis. Shepherd said CPD sends samples to the state crime lab or to private labs.
The state crime lab serves every county in Mississippi and is the only lab out of the state’s network that can perform DNA analysis. Shepherd said it costs $100 to send a sample for testing to the state crime lab. Depending on the backlog, he said, it can take up to six months to get results. Private labs can work faster — he said they can have results back in a month or two — but are more expensive.
Hughes said the lab has seven DNA analysts who look at samples collected from crime scenes. The state’s four labs have workers that do serology- analyzing samples to see if they contain physical evidence such as blood, semen or epithelial cells. Each lab can have 50 to 100 cases at a time, Hughes said.
Not every sample is the same, Hughes added. Some, such as bodily fluids, are easier to work with, compared to trace samples that require more intensive testing methods.
“Blood and semen have a lot of DNA,” she said. “Touch DNA, when it’s just a small number of cells — in cases like that, we do have to use a different type of extraction technique to be more sensitive and get whatever out of it we can.”
How long analysis takes depends on the case. Hughes said sexual assault cases receive priority treatment. Serology can take 30 to 45 days, and DNA analysis can take up to another 45 days.
Once an analysis is complete, samples that meet the FBI’s eligibility guidelines are entered into the CODIS system. For criminal cases, the samples have to be from a perpetrator or attributed to a crime scene. Victims’ DNA is not entered to the system. Hughes said the FBI audits labs stringently to make sure guidelines are followed.
If the analysis produces an immediate match, the lab notifies the investigating agency. Otherwise, it remains on the database in hopes of one day producing a hit.
The CODIS system, as a whole, contains samples from offenders, arrestees, unidentified human remains, missing persons and relatives of missing persons.
In April, according to the FBI, the system contained 110,058 offender profiles; 1,903 arrestee profiles; and 1,290 forensic profiles for Mississippi.
Hughes said the state lab can search the state database system daily and uploads samples every day to the national database. The national database runs searches twice a week.
Mississippi 16th Circuit District Attorney Scott Colom said DNA analysis is one of the best tools available in the criminal justice system, especially for sexual assaults and violent crimes.
“The thing you want to do when you’re dealing with victims and people accused of crimes is to make sure the right person is prosecuted and convicted,” he said. “…If it’s collected properly, properly analyzed and properly stored, the results are as close to certainty as we can get in the criminal justice system. It’s an absolutely critical tool to finding out the truth.”
DNA, while very useful, isn’t a common tool. Colom said drug cases make up about a third of the district’s cases, and DNA isn’t any help for those. He said the evidence also isn’t very helpful for property crime. But for violent crime cases, he said it only comes into play about 15 percent of the time.
Colom pointed out that DNA’s usefulness cuts two ways- both for producing convictions and exonerating the innocent. Both, he said, are crucial functions for providing justice for everyone.
“As a district attorney and a prosecutor, my job is to do justice,” he said. “To the extent that anybody has been wrongfully prosecuted or wrongfully convicted, if DNA can exonerate them, that’s just as good as me being able to convict somebody. I take the duty of providing justice seriously, and that means not only protecting the rights of the victim, but also protecting the rights of the accused.”
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