1 INTRODUCTION

Despite research supporting the influence TBIs can have on inciting violent behavior, proving it for the purpose of determining culpability within the confines of the criminal justice system has been extremely challenging, especially for cases that do not provide obvious or disfigured bodily clues. The importance of visual, tangible evidence cannot be overstated within the courtroom, but what happens when formless thoughts, cognitive functions, emotions, and behavior distort and malfunction due to injury? Without observable parameters, it is difficult for those who determine an offender's fate to understand the injury's potential impact.

TBI graphing (implementing the interpreted results from in-depth, color-coded reverse chronology) was developed in response to the massive amount of data available in CW's case, which needed to be organized and expressed visually for observation and comprehension. The results demonstrate that this method may serve as a beneficial tool within the forensic sciences.

2 BACKGROUND

On August 1, 1966, CW stabbed his mother (matricide) and wife (uxoricide) to death between midnight and 3 a.m. and later that day killed 14 others (including an unborn baby) with firearms on and from the observation deck of the 307-foot tower on the University of Texas at Austin (UT-Austin) campus. Over 30 more were wounded and another victim died in 2001 (related to the injury). Two police officers ended CW's life, at the age of 25 (DOB: 06/24/1941), with shots to the head and heart just over 90 min later.

CW, who was an accomplished pianist and had reportedly become the world's youngest Eagle Scout at the age of 12, was approximately a year away from earning a bachelor's degree in architectural engineering from the institution. Only 4 days prior to the disaster, he made a payment on a class ring, received praise at the conclusion of a lab assistant position, and was studying for exams. Objective clues that the tragedy was impending did not manifest until about the day before. Doctors, appointed by Texas Governor John Connally to investigate the event, were unable to determine the definitive cause of CW's actions (for numerous reasons), but reported that research of the time recognized it may have had a biological source. The only symptoms they considered to demonstrate brain injury at that time were changes in “speech, gait, face, or hand movements [1].” Since no changes were reported, brain injury was not considered.

U.S. President Lyndon B. Johnson, who had a friend and acquaintances personally impacted by CW's actions [2], instructed Federal Bureau of Investigation Director J. Edgar Hoover to investigate the event. Not wanting to overstep the authority of local and state law enforcement agencies, the FBI assisted as much as possible without taking the lead. In the rush to find answers, every aspect of CW's life was examined and scrutinized. Immediately, several factors stood out: a small (approximately 2 cm × 1.5 cm × 1 cm) [3] glioblastoma multiforme (GBM) [1] found in the white matter near the right amygdala during the autopsy, his father's abuse throughout childhood, an amphetamine addiction, and the unusual number and types of physical trauma events he encountered in his short existence (Table 1).

3 SUBJECT OVERVIEW

As a child, CW was considered above average in several parameters. His IQ tests scored 138.9 at the age of 6, 120 at 12, 116 at 15 and 127 around 18. He attended a private kindergarten at 3, started piano lessons at 5, studied Latin at 9, excelled in scouting and earned the Ad Altare Dei Award at the age of 12. Academically, he consistently scored in the top 5% on standardized testing before high school and maintained above average grades during his freshman and sophomore years. CW's academic performance substantially declined, especially in math and English, and incidents of moodiness/quick-temperedness were reported during his junior and senior years. During the investigation, witnesses reported that CW was severely assaulted (and nearly drowned) by his father close to his 16th birthday in June 1957. CW was treated for an infection to the left side of his face that required “an incision for drainage” not long after and acute appendicitis (appendectomy) approximately 3 months later. Surgery to cut adhesions that developed on the colon followed [4].

Less than a year after the assault, CW was involved in a serious motorcycle accident (possibly two). Following this incident, he suffered from headaches and abdominal issues, and incurred numerous traffic violations, for the remainder of his life. To escape his father, he joined the U.S. Marine Corp as soon as he turned 18. While stationed at Guantanamo Bay, Cuba, lightning struck a nearby telephone pole, traveled through the line, and exited through CW while he was using a phone booth. According to U.S. Naval Hospital records, the phone turned white and he was thrown against a truck. Despite being treated for nausea, a numb ear, and headache, CW requested to return to duty the following day (USN, personal communication, April 27, 1960). A few months later, CW began the rigorous process of applying for a scholarship through the Naval Enlisted Scientific Education Program. It was an incentive opportunity developed to entice gifted individuals interested and adept in science and engineering to pursue long-time careers in the military and provide a path to becoming an officer. By February 1961, he was accepted and, in June, participated in a summer course at the Naval Preparatory School in Bainbridge, Maryland to help ready him for the transition to a university.

Following a new friend that he made there, he enrolled at UT-Austin as a mechanical engineering major. During the first fall semester, his grades were far below what he felt he was capable of and below scholarship requirements. At the start of the next semester, CW was injured in a rollover accident in a Corvette convertible. Two months later, he was “placed on academic probation for having a grade below C and for failure to maintain minimum overall academic average (FBI SAC WFO, personal communication, August 3, 1966).” In August 1962, he married his future victim, who was also a student at the university. With still poor grades that fall, he lost his scholarship and returned to active duty in February 1963. Back at the Guantanamo Bay base that September, he was involved in another rollover accident down a 25-foot embankment, this time in a military jeep (Marine Corp, personal communication, September 10–12, 1963). CW fell unconscious for several hours after rescuing the passenger who was pinned underneath. Less than 2 months later, he was court-martialed and served a short time in the brig for unrelated issues. The court-martial resulted in a demotion from lance corporal to private and 30 days of confinement with 90 days of “hard labor.” It was at this time that he created the well-publicized personal journal.

When CW discovered (in March 1964) that he would be honorably discharged early in December, he already began preparing to return to UT-Austin to finish a degree. Two months before being discharged, a group of Marines accosted CW and a friend while walking back to their room after midnight, knocked him to the ground, and kicked him numerous times in the head (FBI SAC, personal communication, August 3, 1966). The attack was deemed a case of mistaken identity. By January, he was back at the Austin campus, but changed his major to architectural engineering. Interestingly, despite additional extensive injuries, his academic performance improved upon his return. His lowest grades of C would still be in mathematics or courses requiring it, however. By the fall of 1965, a friend had observed that the pressures of his courses and hours involved in studying were beginning to strain CW (J. Cole, personal communication, August 16, 1966). His determination made him do whatever it took to keep up, including increasing the use of drugs and decreasing sleep. This would be the pattern that eventually unraveled by the next summer.

Regardless of the years of abuse, CW did not appear to demonstrate any outward hostility toward his father until about the end of November 1965. That is when CW shared a story with a friend about his father's capacity for violence. CW and his youngest brother were hunting with him when at some point during one of his rages, the father assaulted his youngest son and pointed a rifle at him. In response, CW pointed his rifle at their father and made it clear he would kill him if he ever did it again. CW told his friend it took all restraint “to not pull the trigger at that moment (FBI SAC SA, personal communication, August 4, 1966).” A significant event occurred 5 months before the tower tragedy when CW's father threatened to harm his mother at their Florida home, involving the police. In response, CW immediately left Texas and drove straight through to retrieve her. Witnesses told investigators that 2 weeks later CW was very behind in his schoolwork, suddenly sold his books and slide rule, and advised a friend that he was leaving because he “had something personal to settle.” Friends and an instructor convinced him to stay in school.

Another friend convinced CW to see a professional at the university's health center since he had admitted to pushing his wife and being concerned about his temper and overwhelming stress. Toward the end of that same month, CW did meet with two university doctors, one who prescribed Valium. CW told the other that he was having thoughts of shooting people from the tower [5]. After that meeting, he never returned. During this time, his father was still calling Texas constantly, begging for his wife's return, and making threats (J. Barron, personal communication, February 7, 1967). CW and his mother both feared for her safety. By May, witnesses stated that CW often went without sleep for days (likely with the help of amphetamine). Amidst the chaos, he still managed to complete 19 h (more than a full load) with a B average.

It is believed he and his mother made two trips to Florida during May, as well. In the month leading up to the tragedy, CW maintained a challenging schedule of classes, work, travel, hosting family and friend visits, dealing with family issues, and representing himself in court to contest a ticket. Even with his overwhelming responsibilities, witnesses told investigators that CW seemed happier than ever and saw no evidence of depression, aggression, or other emotional problems. Two days before the tragedy, CW's father allegedly announced that he was terminating financial assistance to CW and his mother (J. Cole, personal communication, August 17, 1966). Although there were no witnesses to CW's feelings about this, many people believed that this was the trigger. The following day, CW purchased some canned goods, a Bowie knife, and a pair of binoculars. He then took his wife to a movie and met with his mother for lunch. Later that afternoon, CW and his wife visited friends. At 6:45 p.m., after his wife returned to work, he wrote about his plan to kill them later that evening.

CW murdered his mother first (at her apartment) shortly after midnight and then his wife, sometime between 2:15 and 3 a.m., when he returned home. The next and last murder spree began at about 11:40 a.m. on the university's tower observation deck and lasted until about 1:24 p.m.

4 MATERIALS AND METHODS

Open-source data and information involving CW were gathered from numerous sources with pertinent details arranged in reverse chronological order (from tragedy to birth) and color-coded using Excel to view relationships and progressions. Data and information were collected from: in-person research at the Dolph Briscoe Center for American History at the UT-Austin campus; electronic correspondence and file transfers from the Austin History Center; National Personnel Records Center; books; magazine and newspaper articles; reputable online resources and articles with references; and telephone interviews and/or correspondence with a family member, close friend, NASA coworker, fellow serviceman, and high school classmate of CW. Much of the data involved records generated and gathered by the Austin Police Department, FBI, military, Bureau of Drug Abuse and Control, other law enforcement/government agencies, and CW's personal collection.

Every effort was made to use primary sources when possible and cross-reference information to examine the data for accuracy. If conflicting data surfaced, it was tested using various methods. If the conflicting data had no resolution and did not appear relevant to the research, it was omitted. If the conflicting data was relevant, it was included and the conflict noted. Data considered reliable with only one source was included in the chronology and sources were identified.

Resultant data was then compared to available research and case studies involving or relating to TBI and associated secondary injuries. Incidents of possible cognitive, behavioral, and emotional TBI sequelae were evaluated based on interpreted atypical causalities and responses. This method is limited due to the lack of full context of each incident, potential subjective witnessing, and other factors; however, in many cases trends of information were provided from sources unknown to each other, which assisted in evaluations. With this information, a graph was created comparing potential TBI sequelae with time of occurrence to the timing of injuries and aging (Figure 1).

5 RESULTS

In CW's case, TBI graphing visually expressed a timing relationship between potential injuries, sequelae start, and sequelae progression. Reverse chronology also revealed that at the time of the tragedy, numerous TBI aggravators were present. In relation to the number and nature of potential TBI sequela occurrences, two periods of time especially stand out: November 1963 to November 1964 and March to August 1966. CW experienced the potential moderate TBI from a rollover accident in September 1963. CW's GBM was estimated to have started forming between August 1965 and March 1966. Members of the Connelly Commission believed the tumor would have ended his life within a year.

With the influence of TBI being expressed through the graph and chronology, further investigation into the findings can be used to strengthen the case for relationship. Although CW's autopsy and commission results were limited in scope for numerous reasons, multiple physical anomalies were identified, including: the GBM; much thinner than normal skull thickness; and slight flattening of convolutions. The Connally Commission pathologists also observed that CW's white matter regions had a brownish tint. In addition, they recorded: “slight mineralization of blood vessels in the globus pallidus, an occasional lymphocyte in perivascular spaces, subpial amyloid bodies, and slight periventricular gliosis in the occipital regions.” The doctor who performed the initial autopsy also noted that CW's kidneys were “relatively large” and had “some congestion along the borderline of the two layers,” and his liver was proportionally large and contained pale brownish-yellow matter and a “decreased amount of blood.” (The commission reported no changes in CW's liver and kidneys.)

Members of the commission agreed that CW's abnormal aggressive behavior may have been caused by brain disease, but (with the knowledge of the time) they could not find any pathological evidence. CW's brain had been severely shredded when shot by the officers and dissected into reportedly hundreds of pieces (during the autopsy) before ever reaching the commission. Like diffuse axonal injury (which is suspected in CW's case), a tumor can also lead to the damage of axons and their sheaths at its site, which in turn affects the routing of data. There are also biochemical responses to tumors, such as inflammation, and symptoms related to its location, size, and nature. The presence of the tumor may also have been evidence of TBI. Head trauma can cause cell death and damage, inflammation, and changes in biochemical and electrochemical processes – all elements that can create conditions ripe for mutations in cell division (especially in already weakened tissue). When inflammation is prolonged, data suggests that the chemicals that flood into the injury site in response can contribute to oncogenesis due to their mutagenic properties [6]. In 2016, researchers were able to find radiographic evidence that showed tumors had developed at the same site of a brain injury in two cases [7]. So, it is plausible that an excessive amount of repeated head trauma could have caused such a tumor. Another factor that may have influenced GBM formation was his exposure to toxins, including vinyl chloride, while stationed at Camp Lejeune [8]. Following case studies of workplace exposure, vinyl chloride appears to be a possible risk factor for developing GBM [9]. Other reported risk factors for gliomas include certain genetic profiles and exposure to ionizing radiation and electromagnetic fields [10].

CW's skull thickness was measured between 2 and 4 mm. A 1975 U.S. study (chosen to more closely match CW's parameters) found the mean skull thickness of sample Caucasian males, between the ages of 20–29, to be: 7.7 mm for the frontal; 6.5 mm for the upper parietal; 7.5 mm for the lower parietal; and 5.7 mm for the occipital [11]. Considering CW's frame was 1.83 m (6 feet) tall and approximately 90 kg (198 pounds), it is evident that his skull was much thinner than normal for some reason. There are three main reasons that a skull will become thinner (or thicker) than average: a genetic anomaly, physical influence (i.e., environment, diet, disease, and/or injury), or a combination of the two. Though the genetic influence cannot be ruled out, the odds of it being a factor are low since it tends to lead to malformation. Given his history of childhood abuse, numerous injuries, and chronic infections, having a thinner skull is reasonable due to chronic inflammation. CW's clues of potential chronic inflammation are telling since prolonged inflammation can “contribute to worsening outcomes of the progressive TBI pathology” and may be “the most important cause of post-traumatic neurodegeneration including CTE (chronic traumatic encephalopathy) [12].” Research has shown that TBI or chronic inflammation could also be a potential contributing or resulting factor for the other findings of the commission in 1966, including: discoloration of white matter (due to demyelination), mineralization of blood vessels [13], lymphocytes in perivascular spaces [14], amyloid presence [15], and periventricular gliosis [16]. TBI has also been linked to liver and kidney inflammation [17]. Skull thickness is considered an influential factor in the outcome of a head trauma [18].

Private and military medical records revealed CW suffered from numerous immunological issues from toddler-age until death. Some conditions, like tinea versicolor, were chronic. It is widely acknowledged that there is a direct correlation between TBIs and immunosuppression [19]; however, outcomes can differ greatly depending on many factors. The type, severity, and length of time of the inflammatory response appear to be major elements.

6 DISCUSSION

The link between TBIs and violent behavior has been observed and studied for at least several decades. Scientific investigation into its association with the rare event of mass killings, however, is relatively new. In 2014, UK researchers published findings from their comprehensive study that analyzed the psychosocial and neurodevelopmental risk factors in mass murderers and serial killers. Of the 239 mass killers that met certain criteria for their study, 44% had evidence of autism spectrum disorder and/or TBI [43]. The team also discovered that 81% of the killers who had experienced a definite TBI had also been abused as children, witnessed their parents physically fight when they were young, or encountered other psychosocial stressors. Expanded research, involving a wide range of adverse childhood experiences (ACE), has found that as the number of endured ACEs increases, so does the likelihood of the affected individual committing violent acts as an adult [44]. ACEs can be traumatic events (i.e., physical/emotional abuse, witnessing domestic violence, serious accidents, bullying victimization, and more) that threaten the wellbeing of a child age 17 or under. The factors contributing to these violent outcomes are complex, multifaceted, and still not fully understood.

For an injured brain, one aspect of how violence can manifest may be the decreased ability to control the behavior. Recent scientific studies with mice have been confirming decades of observations that people exposed to repetitive head injuries are more at risk for developing disinhibition [45], or lack of restraint in functionalities. This can include behavioral, emotional, cognitive, perceptional, and even instinctual. In CW's situation, his violent actions were the result of decisions – not a spontaneous loss of control. However, research is also affirming that TBIs can impact the ability to make decisions that may require self-control. In 2017, a team from the UK, Spain, and U.S. demonstrated that the ability to stop unwanted thoughts may depend on hippocampal gamma-aminobutyric acid (GABA) [46]. Since TBIs can result in a decrease in GABA levels and increase in GABAergic dysfunction [47], a decrease in inhibiting thought may correspond. Symptoms of low GABA that coincide with CW's sequelae include: substance abuse/addictions, insomnia/short sleep cycles, mood disorders, and sugar cravings. Inhibitory control is also directly related to the proper functioning of the axonal initial segment (AIS) [48], as well as the excitatory and inhibitory neurons, specialized regions in the brain, and numerous complex processes that impact them all. AIS switches can obviously be impaired during a TBI, but they are also susceptible to the secondary factors that affect the rest of the neurons and their sheaths (e.g., neurodegenerative diseases, inflammation, neurotoxicity, etc.). Potential amygdala dysfunction may have been another element influencing CW's violent actions. Despite the GBM's location, the Connally Commission made no mention of the possibility in its report. The doctor who performed the autopsy also felt it was not a contributing factor. Though some still speculate that the tumor may have altered his behavior due to its influence on the amygdala (and other factors), research has shown that TBIs [49], amphetamine use, SD, and stress [50] are all factors that can disrupt its operation (especially if they are all potentially influencing the amygdala at the same time, as in CW's case). Benefits of the graph and reverse chronology include the ability to demonstrate that there was a pattern of potential TBI sequelae, change, and progression before the tumor's development, which implies neurodegenerative processes. This observation creates a line of inquiry that would benefit from additional research.

When determining criminal culpability, the situation becomes more complex when we consider the possible impact TBIs have on conscious and unconscious input for decisions-making. For an individual with an undiagnosed TBI, the conscious and unconscious may use distorted data (collected from injured structures and impaired processes) to draw conclusions which could develop into a destructive pattern of reinforcement that degrades functioning over time. Both conscious and unconscious decisions could become precarious. Without context, the individual would be oblivious to why it is happening.

Circumstances surrounding potential TBI-influenced violence cases can be complex and each one may have its own unique characteristics. In some cases, there may even be TBI recovery and rehabilitation over time. TBI graphing and reverse chronology may provide an observable method to analyze the time relationships between injuries, sequelae, and those degenerative or rehabilitative changes, which may assist in determining accountability, appropriate care, and/or parole opportunities.

7 CONCLUSION

Using the complex case of CW as an example, TBI graphing and reverse chronology provided an opportunity to visual view the relationships between potential injuries, sequelae, progression, and aggravators prior to an exceptionally violent event. These tools may provide a useful and observable means to examine the possible role TBIs have in inciting violent behavior, which may aid in determining criminal culpability. This method may also help foster understanding of TBI-influenced violent behavior among those tasked with determining an offender's fate.

CONFLICT OF INTEREST STATEMENT

The author has no known conflicts of interest.