Charles Whitman Jr. was a marine before enrolling in the University of Texas. He suffered from mental illness. He saw doctors and expressed his concern however the only prescribed him medicine.

Atavism implies that criminals are born that way. Whitman's father was abusive when he was younger towards his mother and also him. In the early stages of his married, he abused his wife. His father also taught him about guns, by age 12 he was an expert shot.

The body chemistry theory implies that biological theories utilize chemical influences, including hormones, food additives, allergies, vitamins, and other chemical substances and the impact of weather to explain criminal behavior.

Whitman had seen various doctors in the past and they had all prescribed him some type of medication. He was also a regular user of Dexedrine, an amphetamine.

The modeling theory implies that people learn how to act by observing others. Whitman's father was abusive, so he was abusive to his wife.

Whitman left suicide notes in which he asked that an autopsy be done of his brain. It was discovered that he had a tumor. It was concluded in a second autopsy that the tumor could have had an influence on Whitman's actions.

It was believed that the tumor contributed to his inability to control his emotions and actions as a couple of times he said, "I don't know what's causing me to write."

Charles Joseph Whitman. (2013). The Biography Channel website.