On a spring evening in the mid-80s, 18-year-old Teresa Branch and her friend, Lisa, were having car trouble. Teresa’s red Pontiac Sunfire kept stalling out, causing her to pull off and park in an apartment complex lot. Because her home was only a half-mile away, Teresa decided to run back to the house and get help while her friend stayed behind with the car. It was just an hour later that a truckload of teens spotted Teresa’s lifeless body in the parking lot of the Harmony Baptist Church in Arlington. She had been raped and shot below the heart with a large-caliber gun.
When Teresa was murdered, the use of DNA in criminal cases was barely emerging. As DNA research advanced over the years, biological evidence that was recovered from the crime scene yielded a DNA profile. However, comparisons to suspects led nowhere, and there were no matches in the national DNA database.
Last month, more than three decades after the horrific crime, Arlington police released a composite sketch of the suspect. In a recent interview, Arlington police Sgt. VaNessa Harrison said, “Thirty years ago when we collected this evidence, we had no idea what the technology would be today.”
DNA phenotyping is the latest tool being used by investigators to solve murders. Parabon NanoLabs, based in Virginia, analyzed a DNA sample from Teresa’s case to predict the suspect’s physical appearance, including hair and eye color and ancestry. This technology also makes it possible to predict skin color, freckling, baldness, hair curliness, tooth shape and age.
Teresa’s two brothers, her mother and father were left to mourn the loss of their family member. Her mother, Mercedes Branch, shortly thereafter experienced a nervous breakdown resulting in admittance into a psychiatric care facility. Months after her daughter’s death, Mercedes died from a prescription medicine overdose.
While no arrests have been made, it’s hopeful that the sketches will prompt solid new leads. It’s the intention of law enforcement to bring peace and closure to the families of the victims left with lingering questions about what happened to their loved ones. Rates in which crimes are solved and guilty verdicts are secured greatly rely on how quickly technology advances.
Forensic Division Manager for the Fort Worth Police Department, Michael Ward, is responsible for the administrative, operational and quality management at the crime lab on East Lancaster. Ward is also on the Texas Forensic Science Commission's Licensing Advisory Committee. He says, “Texas has become the first state to require a forensic license. You have to get a license to be a doctor, a nurse, a beautician, but there was nothing in place for forensic analysts.”
Michael Ward, Forensic Division Manager for the Fort Worth Police Department
Accreditation of crime laboratories is required in Texas; however, certification of individual forensic scientists is not currently required. During the 84th legislative session, the Texas Legislature passed a bill requiring all forensic analysts in Texas to be licensed beginning Jan. 1, 2019.
Ward runs a tight ship and says that preserving the integrity of the evidence is not simply a lab function but a function of everyone involved. “It is critical that the legal chain of custody is maintained … If the chain of custody has not been properly documented, attorneys can argue that the evidence is not admissible in court,” he says.
It takes a strong constitution and certain mentality to do this type of work. “I remember years ago, a young woman who had attained her masters in forensics science and got a job in our biology unit. It’s what she had always wanted to do. After six months, she left her employment with the crime lab. She had been assigned to screen sexual assault kits, and reading the reports got to her. It was sad to see someone work so hard to get their degree and then find out this field isn’t for them,” Ward says.
According to Ward, the industry has evolved significantly since he began in 1994. “This used to be a male-dominated industry, and today we have more women than men working in the crime lab.” He also thinks the multitude of crime shows depicting criminal investigations and the crime lab functions is unrealistic. Glamorizing forensic scientists on these shows has made the field more popular and intensified competition for positions. “I only wish it was as simple as they make it look in those shows. You can’t wear high heels and a skirt; this is a dirty job. You might be climbing up on a water tower to take photographs or digging something out of a river or a lake. It’s nothing like they portray on TV,” Ward says.
Instrumentation and complex computer programs have evolved how crime scenes are processed. “You used to sketch a scene by hand and could then turn it into a diagram; then we moved into computer-generated scenes, and now we have digital screening instruments. This state-of-the-art equipment typically does multiple 360-degree scans to fully capture a scene. Where you might have left something out of a sketch years ago, now with Point Cloud technology, it’s all right there. You can tell the distance between paintings hanging on the wall or the measurement from the victim’s left hand to their right hand,” Ward says. “Technology is constantly evolving the science in this field.”
Several government and private forensic databases can help law enforcement and the scientists who support their work in the lab. Not only are there databases for DNA and fingerprints, but also sophisticated systems in place for investigating tire tracks, footprints, ink, glass and paint chips. These databases allow law enforcement to share information and cooperate easily, making them more effective in solving cases.
In the late ’80s, the federal government built the foundation for a system of national, state and local DNA databases for the storage and exchange of DNA profiles called CODIS, the Combined DNA Index System. CODIS can compare crime scene evidence to a database of DNA profiles obtained from convicted offenders and link DNA evidence obtained from different crime scenes, thereby identifying serial criminals.
For CODIS to be used to its full potential, states began passing laws that required offenders convicted of certain offenses to provide DNA samples. Now the federal government and all 50 states require DNA samples to be collected after certain offenses. “Fort Worth has one of the highest CODIS hit rates in the country,” Ward says.
Methods utilized within the FWPD Crime Lab’s Latent Print Unit involve alternate light sources, superglue
processing,magnetic and fluorescent powders, dye stain techniques and computerized digital imaging.
Fingerprint photos provided by the FWPD Crime Lab.
The National Integrated Ballistic Information Network (NIBIN) is the only automated ballistic imaging network in operation in the nation that automates ballistics evaluations and provides investigative leads in a timely manner. Firearms examiners enter cartridge casing evidence, which is compared against the database and allows law enforcement to search against evidence not only in their jurisdiction, but against neighboring jurisdictions and across the country.
Employing technology to automate the processing of arrest and applicant fingerprint card reporting to the DPS, the Automated Fingerprint Identification System (AFIS) is capable of processing a fingerprint submission in a fraction of the time it takes using the manual process. A network of remote input devices located at police departments and sheriffs’ offices throughout Texas give access for local law enforcement.
A national fingerprint and criminal history system maintained by the Federal Bureau of Investigation also exists, known as IAFIS, the Integrated Automated Fingerprint Identification System. Maintaining the largest biometric database in the world, the IAFIS contains the fingerprints and corresponding criminal histories for nearly 50 million people.
Other elaborate coordinated systems are in place to efficiently store and share forensic information, such as the National Automotive Paint File, which contains more than 40,000 samples of car paint from manufacturers. A Glass Evidence Reference Database contains 700 glass samples for comparison, and TreadMark, a commercial product, uses pattern, size, damage and wear to identify individual outsole impressions and compares them with the shoe print data from suspects in custody and crime scenes.
Forensic biologists deal with subsets of physical evidence that contain DNA, such as hair, semen, saliva and various tissues. They may also examine bones, insects or plant and animal remains to support criminal investigations in determining the time and cause of death.
DNA can now be used to provide police with a composite phenotype profile of a suspect (see sidebar: Developments in DNA). Another relatively new development is the Touch DNA Method. It analyzes skin cells left behind when criminals touch victims, weapons or anything else at the crime scene. Cassie Johnson, forensic supervisor of the Biology Unit of the FWPD Crime Lab, says, “Because humans shed tens of thousands of skin cells each day, they can be transferred to any surface the person touches.”
Johnson explains that often, deciding the order in which the lab processes biological evidence can be a tough call. “Let’s say you have evidence from a homicide case where the suspect is in jail and he won’t be in court for a year, and at that time you also have evidence from a case where there is a prolific burglar that hasn’t been apprehended and he is repeatedly hitting businesses or homes. We need to decide what is our priority,” Johnson says.
Sharon Patton, a senior forensic scientist in the Chemistry Unit of the FWPD Crime Lab,
performs presumptive tests in the lab to determine general characteristics of the sample.
Law enforcement officers or investigators out in the field will often employ a presumptive test to analyze a found substance. This form of analysis is presumptive only and helps the officer determine if the substance could be illegal so he or she knows the appropriate action to take. The collected material is then submitted to the Chemistry Unit of the Crime Lab.
FWPD’s Chemistry Unit basically has two primary functions. It examines for controlled substances and performs toxicology for blood alcohol content. Each laboratory has procedures for analyzing evidence. In general, the analysis includes a weight test, presumptive screening and confirmatory testing.
Sharon Patton is a senior forensic scientist in the Chemistry Unit of the FWPD Crime Lab. She explains, “Presumptive tests in the lab are done to determine general characteristics of the sample, and that allows us to narrow down what further testing will be done.”
Confirmatory testing is more in-depth and includes the separation and identification of the material. Once the components are separated, highly advanced instruments are used, such as a mass spectrometer or infrared spectrometer for identifying each component.
Patton’s workspace is covered in evidence envelopes full of unidentified pills and other illicit drugs. She explains that one of the challenges she encounters in her work with synthetic drugs is that manufacturers continually change the formula. Once an ingredient becomes controlled, they quickly replace it with something else.
Once substances have been collected by law enforcement officers, they are submitted to the crime lab for testing.
The term “latent” implies that prints are not easily detected or seen without the aid of equipment or physical, chemical, photographic or electronic development. Prints collected can be from fingers, palms, feet or virtually any area of friction ridge skin impressions. Fingerprints that weren’t detectable in the past can now be developed with some of the new techniques and technology.
The two fundamental principles that lend merit to the science of fingerprint analysis are as follows: (1) Fingerprints are persistent in that they remain unchanged throughout the life of an individual, from before birth until after death, barring significant injury or disease. (2) No two people have ever been found to possess the exact same fingerprints, or the exact same friction ridge characteristics in the exact same formation. Before the advent of automated fingerprint databases, when a latent fingerprint was the only clue, comparing it to hundreds of thousands fingerprint cards was a severely arduous task.
Firearm & Toolmark
To understand this unit of the crime lab, it’s necessary to know the basics. Firearms have several metal parts. When a gun is manufactured, the machining process leaves distinct, microscopic markings on some of these parts. When a firearm is discharged, the tool marks are transferred to the fired cartridge casings and bullets. Additional imperfections may arise from use over time that can be easily detected.
In the Firearm and Toolmark Unit of the FWPD Crime Lab, forensic scientists test, recreate and
examine bullets, cartridge casings and other weapon or tool marks.
Firearm examiners can also analyze for distance determinations, operability of firearms, serial number restorations, ejection patterns and trajectory, as well as compare tools with the tool marks found on the crime scene. For instance, chisels, hammers, wrenches and many other tools can create impression tool marks, defined as any marking created by one object on another.
As people place more and more of their lives online, digital forensics has taken on a larger role in court cases and criminal investigations. In addition to catching murderers, computer forensics has led to the conviction of many terrorists, who utilize the internet to recruit members, and sexual predators, who use social networks to stalk their victims.
Lorelei Peterson, Forensic Scientist
Created in 2004, the FWPD’s Digital Forensic Laboratory (DFL) is a support unit within the Criminal Investigations Division. Examiners in this division are capable of acquiring data from seized computers, mobile devices and surveillance video. They are also able to locate information that a criminal thought they may have deleted but is actually still on the drive. Global Position System (GPS) software embedded in smartphones and satellite systems also act as an aid in tracking the location of a suspect.
Key to the Past
The University of North Texas Center for Human Identification (UNTCHI) combines its forensic anthropology and DNA expertise to aid investigations of missing persons and unidentified remains. Its forensic anthropological team evaluates and analyzes skeletal trauma to aid criminal investigations and assists in cause and manner of death determinations.
Bruce Budowle, Ph.D., is executive director of UNTCHI and a highly regarded global expert in the field of forensic genetics. His experience includes 26 years at the FBI laboratory developing, validating and implementing DNA typing methods used worldwide. Budowle was also one of the original architects of CODIS.
Paul Slocum, Senior Forensic Scientist
“The array of services we provide makes us one of the most comprehensive forensic DNA laboratories in the United States. In addition to partnering with agencies across the nation to assist on criminal investigations through anthropological and forensic DNA casework analyses, we also manage missing persons programs, use DNA to combat human trafficking, conduct research and development, and provide training to students, scientists, law enforcement personnel and the legal community,” Budowle says.
NamUs, the National Missing and Unidentified Persons System, is a national clearinghouse for information related to missing or unidentified persons cases across the United States. Through secure online databases, medical examiners, coroners, law enforcement officers, family members of missing persons and concerned citizens can access varying levels of information in NamUs to assist in the resolution of thousands of unsolved cases.
NamUs also provides data management and forensic resources for missing and unidentified cases at no cost to investigating agencies or searching family members. Currently there are more than 950 missing people registered in Texas.
A collaboration between NamUs and the FBI’s Latent Print Unit has resulted in hits to 206 unidentified person cases in less than eight months. In February 2017, the NamUs Fingerprint/AFIS Unit and the FBI Latent Print Unit initiated a project to ensure that all fingerprint images submitted to NamUs for unidentified decedents (the term used for a deceased person whose identity is unable to be determined) are searched through the FBI's Next Generation Identification (NGI) system.
Of the 206 hits to date, case resolutions resulting from this project include:
• A 1978 double homicide involving victims found in Arkansas and Missouri was renewed after one victim was identified, providing a new lead to the second victim’s identity.
• A missing migrant was identified as a decedent found in Tennessee in 2015.
• A missing man suspected of murdering his girlfriend in 1993 was identified as a decedent killed in a pedestrian-automobile accident in New Jersey that same year.
• A decedent found floating in a Washington waterway in 2009 remained unidentified until 2017 because he was never reported missing.
• A man missing from Colorado since 1986 was discovered to have drowned in a Hawaii waterfall one year after his disappearance.
• A homicide victim found in 1986 in an abandoned house in California was identified as a juvenile who was never reported missing.
Future in Forensics
Located a few hours southwest of the Metroplex is Freeman Ranch and the Forensic Anthropology Research Facility (FARF) at Texas State University. It is home to 50 donated human corpses that serve as a resource for forensic anthropology students, researchers, as well as state and national law enforcement agencies.
This 26-acre outdoor human decomposition research lab is the largest of its kind in the world and one of only five in the nation. Students research the decomposition processes for human remains under various conditions. FARF is also used for the training of law enforcement and medical/legal personnel on searching for and recovering human remains.
Formally opening in 2008, FARF was initiated from a need to develop patterns, rates and sequences of human decay in the Texas climate. Research has been conducted on 150 individuals to date, with another 200 living people on the donor list for this unique forensic program.
Professor of Anthropology and Director of the Forensic Anthropology Center at Texas State, Dr. Daniel Wescott, says that all bodies on the ranch are donated specifically as part of the Texas Uniformed Anatomical Gift Act. “We accept two types of donations. There are living donors who have preregistered, completed all the paperwork and come here upon death, but we also accept next-of-kin donations as long as they aren’t estranged from the family member,” Wescott says.
Currently several projects are being conducted at Freeman Ranch. Researchers are examining whether clothing affects scavenging rates, comparing the rates and patterns of the desiccation of the skin to those in colder, drier environments, validating methods of insect development pertaining to interaction with a body and studying microbes in the soil and how those change through the decomposition process.
Wescott says, “Most of our students want to be forensic anthropologists after graduating. Their exposure to watching human remains decompose in a longitudinal manner gives them more experience than many practicing anthropologists. Most of the students are involved in multiple research projects, collecting data to answer questions about how long someone has been dead using a multi-disciplinary approach.”
Robyn Kramer is a graduate research assistant at Texas State. She says that working at FARF has made her fully appreciate the people who donate their bodies to science.
“Without our donors and their families, we would not be producing the outstanding research that can be applied in a variety of contexts. We are extremely lucky in the United States to be able to perform research on decomposition, taphonomy and human variation. Many countries lack the funding or institutional support to perform this type of research, so I feel it is our duty to put in our best efforts and produce information that can impact not only forensics and anthropology, but also society as a whole,” Kramer says.
Once the donor bodies are removed and processed, usually six months to a few years after arriving, they are kept in the permanent Texas State Donated Skeletal Collection. Wescott says, “The skeletons get used for literally hundreds of different research projects.”
Closer to home, future forensic experts can get their education and training in the University of North Texas Forensic Science Program. Through the Graduate School of Biomedical Sciences, students can pursue a Master of Science in Forensic Genetics degree, which prepares graduates for work in crime labs using DNA technologies.
Forensic training, technology and techniques are improving every day. As we continue to hone our capabilities in forensics both inside the lab, out in the field and in the classroom, it will become harder for those committing evil acts to get away with it and leave fewer families like Teresa’s wondering.
photos provided by UNTCHI
Developments in DNA
DNA phenotyping predicts an individual’s physical characteristics from DNA. It can be used by law enforcement to generate leads in cases with the absence of a suspect. By determining how genetic information translates into physical appearance, it is possible to “reverse-engineer” DNA into a physical profile. Parabon NanoLabs — with funding support from the U.S. Department of Defense — developed the Snapshot Forensic DNA Phenotyping System.
Predicting Facial Features Using sex, ancestry and thousands of genetic markers can determine a suspect’s facial measurements, such as lip size and width of the skull. Other physical traits that can be accurately predicted include genetic ancestry, eye color, hair color, skin color, freckling, baldness, hair curliness, tooth shape and age even among individuals with mixed ancestry.
DNA Profiling Versus DNA Phenotyping Traditional DNA profiling, also referred to as DNA fingerprinting, uses DNA as a biometric identifier. Like an iris scan or fingerprint, a DNA profile can uniquely identify an individual with very high accuracy. For forensic purposes, this means that investigators must have already identified and obtained DNA from a potentially matching individual. DNA phenotyping is used when investigators need to narrow the pool of possible individuals or identify unknown remains by learning about the person’s ancestry and appearance. When the suspected individual is identified, traditional DNA profiling can be used to prove a match, provided there is a reference sample that can be used for comparison.
Genomic Ancestry Using DNA phenotyping, a person’s precise ancestry can be determined on a global level. There are seven principle populations in the world: Africa, Middle East, Europe, Central Asia, East Asia, Native American, and Oceana.
Altered Reality A model/sketch of a suspect can be altered by forensic artists to reflect different ages and weights.