Blood Proof
DNA At Heart Of KFC Trial
ABOUT DNA: The double helix, the shape of DNA, bears genetic instructions. Humans shed hair, skin, fingernails, often blood. Forensic experts can use this evidence left behind to reconstruct what happened and who did it. The admissibility of DNA test results in the courtroom has become routine.
Sources and Illustration: The Associated Press, The National Institute of Justice, National Human Genome Research Institute
By KENNETH DEAN
Staff Writer
GARLAND - They work in a lab environment far removed from the grit of a crime scene, but their work can help snare a burglar, rapist and even a killer through advances in science.
Manuel Valadez, Texas Department of Public Safety Regional Crime Laboratory supervisor, said he began his career in forensic science in 1970 and the differences between then and now were like "night and day."
"Back then all we had was fingerprinting and blood typing and all that blood typing could do was exclude suspects and not discriminate against two people of the same blood type," he said.
Valadez and James Nichols, DPS forensic scientist, talked with the Tyler Courier-Times--Telegraph last week about DNA and how the science is being used to solve old cases, including the infamous Kentucky Fried Chicken murders of 1983.
Mary Tyler, 37; Opie Ann Hughes, 39; David Maxwell, 20; Joey Johnson, 20; and Monte Landers, 19, were abducted during a holdup of a KFC restaurant in Kilgore and found slain the next morning along a remote oilfield road about 15 miles away in rural Rusk County. They were shot "execution style."
The scientists did not discuss the case because of a gag order, but did say the lab has been storing evidence in the case since Texas Rangers submitted it in September 1983.
In fact, Valadez said, there are other cases that have been in the custody of the lab for more than 30 years that are now being solved.
"Science has caught up to these crimes and if evidence was stored properly then the person responsible can be tried and convicted," he said. "We knew science would catch up, we just had to wait."
Two cousins from Tyler, Romeo Pinkerton and Darnell Hartsfield, have been charged with the KFC murders and a jury is being selected for Pinkerton's trial in Bowie County.
DNA evidence and the testimony of people who said they saw the two suspects in the restaurant on the night of the murders are expected to be two key pieces of the Texas attorney general's case.
DNA PROFILING
Deoxyribonucleic acid, or DNA, is defined as a nucleic acid that contains the genetic instructions in the development and functioning of all known living organisms.
Nichols said there are 23 pairs of chromosomes in each human cell that make up the human genome and a strand of DNA. These strands of DNA are obtained through hair, skin, blood, semen and saliva samples.
Unlike modern television series that show forensic scientists solving a crime in an hour, the process of extracting DNA and finding a match is a long one that begins when the evidence is obtained from detectives in the field.
When evidence is gathered at crime scenes, it is taken to a lab and then small samples are fed into computers by forensic scientists to see if a DNA profile can be obtained.
The information is then entered into local, state and national databases that compare the samples with DNA from criminals.
Nichols said that in DNA profiling, lengths of variable sections of repetitive DNA are compared between people.
This process can be used by scientists to identify criminals and suspects in crimes. He explained that, except for identical twins, the possibility of anyone having the same DNA was next to absolute zero.
In fact, the mathematical possibilities are usually one in a quintillion that there is a match, and with just more than six billion people on the planet, scientists and law enforcement agree DNA is proof positive of guilt or innocence.
This method is usually an extremely reliable technique for identifying a criminal. However, identification can be complicated if the scene is contaminated with multiple DNA samples.
"It all depends on how the samples are taken, but most of the detectives working crime scenes are knowledgeable and educated in gathering evidence," Nichols said.
Nichols and Valadez said there are variables that can be factors in DNA being extracted from evidence.
"One of the hardest things is to get DNA out of blood that was gathered from dirt, because dirt has organisms that deteriorate the cells in the blood," Nichols said.
Valadez added that heat and direct sunlight also break blood down.
SCIENCE AND PATIENCE
Nichols and Valadez led the way through a maze of rooms making up the Garland DPS Forensic Sciences Lab. Inside were expensive computers, scientists wearing the obligatory white lab coats and freezers containing the DNA evidence of thousands of cases.
One scientist sat at her desk looking for tiny hairs from a SANE (Sexual Assault Nurse Examiner) kit that is part of a sexual assault case. Another scientist lugged boxes filled with brown paper bags full of evidence to a screening table where the items would be checked for any traces of blood, hair, skin or semen.
"What people don't realize is this is not like television and we can't do this in one day and we are not police officers who go to the scene, process the evidence, interview the suspect and make the arrest," Valadez said.
Nichols agreed, saying the process of extracting DNA is a lengthy one.
"From start to finish for us to screen the case, gather evidence and try to obtain DNA profile from it is usually several days," he said.
Nichols said the Garland lab can work between 50 to 100 cases per month, and that each day more cases arrive.
"There is such a backlog that there is a wait time for these cases, and this lab covers 50 counties in Texas," he said.
Valadez said groundbreaking has begun on a four-story laboratory that will increase the forensic science unit's space by 40,000 square feet.
"We will have more room and we will have additional scientists and that will help us work the cases quicker and give us more storage room and more equipment," he said.
Valadez and Nichols said while DNA was able to prove innocence or guilt, they ask law enforcement to be patient, because they are working as quickly as possible.
"It is great to see cases that are more than 40 years old getting solved, and I believe there will be more cases in the future we solve through DNA," he said.
Valadez and forensic scientist Lorna Beasley have testified in cases regarding the KFC murders and are scheduled to testify in Pinkerton's murder trial.
Staff Writer
GARLAND - They work in a lab environment far removed from the grit of a crime scene, but their work can help snare a burglar, rapist and even a killer through advances in science.
Manuel Valadez, Texas Department of Public Safety Regional Crime Laboratory supervisor, said he began his career in forensic science in 1970 and the differences between then and now were like "night and day."
"Back then all we had was fingerprinting and blood typing and all that blood typing could do was exclude suspects and not discriminate against two people of the same blood type," he said.
Valadez and James Nichols, DPS forensic scientist, talked with the Tyler Courier-Times--Telegraph last week about DNA and how the science is being used to solve old cases, including the infamous Kentucky Fried Chicken murders of 1983.
Mary Tyler, 37; Opie Ann Hughes, 39; David Maxwell, 20; Joey Johnson, 20; and Monte Landers, 19, were abducted during a holdup of a KFC restaurant in Kilgore and found slain the next morning along a remote oilfield road about 15 miles away in rural Rusk County. They were shot "execution style."
The scientists did not discuss the case because of a gag order, but did say the lab has been storing evidence in the case since Texas Rangers submitted it in September 1983.
In fact, Valadez said, there are other cases that have been in the custody of the lab for more than 30 years that are now being solved.
"Science has caught up to these crimes and if evidence was stored properly then the person responsible can be tried and convicted," he said. "We knew science would catch up, we just had to wait."
Two cousins from Tyler, Romeo Pinkerton and Darnell Hartsfield, have been charged with the KFC murders and a jury is being selected for Pinkerton's trial in Bowie County.
DNA evidence and the testimony of people who said they saw the two suspects in the restaurant on the night of the murders are expected to be two key pieces of the Texas attorney general's case.
DNA PROFILING
Deoxyribonucleic acid, or DNA, is defined as a nucleic acid that contains the genetic instructions in the development and functioning of all known living organisms.
Nichols said there are 23 pairs of chromosomes in each human cell that make up the human genome and a strand of DNA. These strands of DNA are obtained through hair, skin, blood, semen and saliva samples.
Unlike modern television series that show forensic scientists solving a crime in an hour, the process of extracting DNA and finding a match is a long one that begins when the evidence is obtained from detectives in the field.
When evidence is gathered at crime scenes, it is taken to a lab and then small samples are fed into computers by forensic scientists to see if a DNA profile can be obtained.
The information is then entered into local, state and national databases that compare the samples with DNA from criminals.
Nichols said that in DNA profiling, lengths of variable sections of repetitive DNA are compared between people.
This process can be used by scientists to identify criminals and suspects in crimes. He explained that, except for identical twins, the possibility of anyone having the same DNA was next to absolute zero.
In fact, the mathematical possibilities are usually one in a quintillion that there is a match, and with just more than six billion people on the planet, scientists and law enforcement agree DNA is proof positive of guilt or innocence.
This method is usually an extremely reliable technique for identifying a criminal. However, identification can be complicated if the scene is contaminated with multiple DNA samples.
"It all depends on how the samples are taken, but most of the detectives working crime scenes are knowledgeable and educated in gathering evidence," Nichols said.
Nichols and Valadez said there are variables that can be factors in DNA being extracted from evidence.
"One of the hardest things is to get DNA out of blood that was gathered from dirt, because dirt has organisms that deteriorate the cells in the blood," Nichols said.
Valadez added that heat and direct sunlight also break blood down.
SCIENCE AND PATIENCE
Nichols and Valadez led the way through a maze of rooms making up the Garland DPS Forensic Sciences Lab. Inside were expensive computers, scientists wearing the obligatory white lab coats and freezers containing the DNA evidence of thousands of cases.
One scientist sat at her desk looking for tiny hairs from a SANE (Sexual Assault Nurse Examiner) kit that is part of a sexual assault case. Another scientist lugged boxes filled with brown paper bags full of evidence to a screening table where the items would be checked for any traces of blood, hair, skin or semen.
"What people don't realize is this is not like television and we can't do this in one day and we are not police officers who go to the scene, process the evidence, interview the suspect and make the arrest," Valadez said.
Nichols agreed, saying the process of extracting DNA is a lengthy one.
"From start to finish for us to screen the case, gather evidence and try to obtain DNA profile from it is usually several days," he said.
Nichols said the Garland lab can work between 50 to 100 cases per month, and that each day more cases arrive.
"There is such a backlog that there is a wait time for these cases, and this lab covers 50 counties in Texas," he said.
Valadez said groundbreaking has begun on a four-story laboratory that will increase the forensic science unit's space by 40,000 square feet.
"We will have more room and we will have additional scientists and that will help us work the cases quicker and give us more storage room and more equipment," he said.
Valadez and Nichols said while DNA was able to prove innocence or guilt, they ask law enforcement to be patient, because they are working as quickly as possible.
"It is great to see cases that are more than 40 years old getting solved, and I believe there will be more cases in the future we solve through DNA," he said.
Valadez and forensic scientist Lorna Beasley have testified in cases regarding the KFC murders and are scheduled to testify in Pinkerton's murder trial.
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