"I do not quite understand what it is that compels me to type this letter. Perhaps it is to leave some vague reason for the actions I have recently performed. I do not really understand myself these days. I am supposed to be an average reasonable and intelligent young man. However, lately (I cannot recall when it started) I have been a victim of many unusual and irrational thoughts."
Whitman wrote that he requested an autopsy be conducted upon his body, to determine if there was a biological reason for his actions and increasing headaches. He also wrote that he had decided to kill both his mother and wife. Expressing uncertainty about his reasons, he stated he wanted to relieve his wife and mother from the suffering of this world and to save them the embarrassment of his actions.
Autopsy
Although Whitman had been prescribed drugs, and was in possession of
Dexedrine at the time of his death, no
toxicology test was performed at first because Whitman had been
embalmed on August 1, after the body was brought to the Cook Funeral Home in Austin. However, an autopsy had been requested in the suicide notes left by Whitman, and was then approved by his father.
[92]
On August 2, an autopsy was conducted upon the body of Charles Whitman by Dr. Chenar (a
neuropathologist at Austin State Hospital) at the Cook Funeral Home in Austin, Texas. Urine and blood were removed to test for traces of amphetamines or other substances.
[93] During the autopsy, Dr. Chenar discovered a
brain tumor which he labeled an
astrocytoma, and noted it was approximately the size of a
pecan. He also observed a small amount of
necrosis in the tumor, and concluded that the tumor had no effect on Whitman's actions the previous day. This result was later revised by the Connally Commission (see below).
[94]
Connally Commission[edit]
In the days following the shootings, Texas Governor
John Connally commissioned a task force of professionals to examine the physical autopsy findings and material related to Whitman's actions and motives. The commission was composed of
neurosurgeons,
psychiatrists,
pathologists,
psychologists, and the University of Texas Health Center Directors, Dr. John White and Dr. Maurice Heatly. The Connally Commission did toxicology tests on various organs of Whitman a few weeks after the body of Whitman was exhumed. The toxicology tests revealed nothing significant. They examined Dr. Chenar's paraffin blocks of the tumor, stained specimens of it and Whitman's other brain tissue, in addition to the remainder of the autopsy specimens available.
[95]
Following a three-hour hearing on August 5,
[96] the Commission said that the findings of Dr. Chenar's initial autopsy conducted on August 2 had been in error; that a tumor was found that conceivably could have had an influence on Whitman's actions. Specifically, the Commission's autopsy material, including a paraffin block containing two pieces of brain tumor, were reviewed by Drs. William O. Russell (Head Pathology at MD Anderson Hospital, and Head of the Pathology Work Group of a government study panel), Kenneth M. Earle (Chief Neuropathology Branch, Armed Forces Institute of Pathology), Joseph A. Jachimczyk (Clinical Professor of Forensic Pathology at Univ Texas), and Paul I. Yakovlev (Clinical Professor of Neuropathology and Curator, Warren Museum, Emeritus, Harvard Medical School and Consultant in Neuropathology at Mass General Hospital).
[97] The report, dated September 8, 1966, found that a tumor reportedly removed from the right temporal-occipital white matter by Dr. Chenar had features of a
glioblastoma multiforme, with widespread areas of
necrosisand palisading of cells.
[94] The report also indicated a "remarkable vascular component", which was described as having "the nature of a small
congenital vascular malformation." The psychiatric reviewers contributing to the Connally report concluded that "the relationship between the brain tumor and ... Whitman's actions ... cannot be established with clarity. However, the ... tumor conceivably could have contributed to his inability to control his emotions and actions",
[98] while the neurologists and neuropathologists concluded: "The application of existing knowledge of organic brain function does not enable us to explain the actions of Whitman on August first."
[99]
Forensic investigators have theorized that the tumor may have been pressed against the nearby
amygdala region of his brain. The brain contains two amygdalae, one on each side, and the amygdalae are known to affect fight-or-flight responses. Some neurologists have since speculated that Whitman's medical condition was in some way responsible for the attacks, in addition to his personal and social frames of reference.
[100]
Like, so busy that I wish I had more time to get everything done. 
