Psychobiological and Biochemical factors for Mass Murderers

Case 1: Mass Murder

Andrea Yates was convicted of drowning her five children and given a sentence of life in prison.

Later, it was found that the sentence of life in prison was based on the inaccurate testimony of a highly respected forensic psychiatrist. Her life sentence was overturned, and she was found guilty by reason of insanity and sent to a mental hospital.

Yates suffered from severe postpartum depression and had been hospitalized before she killed her children in an attempted suicide. Her children were Noah (aged seven years), John (aged five years), Paul (aged three years), Luke (aged two years), and Mary (aged six months) when they were each placed in the bathtub, held under, and drowned by their mother.

Yates was delusional and was having persecutory thoughts that were degrading and persecuting her for her motherhood. She was also having command hallucinations telling her she was a bad mother and her children would grow up to be criminals, so she should save them by drowning them.

Case 2: Serial Killer

In 1980, John Wayne Gacy was found guilty of murdering 33 young men. He picked up most of his victims at a local homosexual bar as prostitutes. Other victims were taken home for "interviews" as prospective employees for his construction business.

The remains of 29 victims were found buried under his home while the other four victims had been thrown into the Des Plaines River near Chicago.

Gacy always maintained his innocence throughout the trial and appeals process claiming someone else put the bodies in the crawl space beneath his house. Also known as "The Killer Clown," Gacy used handcuffs (called the "handcuff trick") and chloroform to subdue his victims, and then he would tie a rope around their necks (called the "rope trick") and slowly twist until he squeezed the life out of them.

Gacy had married twice and had two children from the first marriage. Both marriages ended in divorce when his wives found items from his victims or were unhappy from a lack of any sexual contact between them. During both marriages and afterwards, Gacy was considered an outstanding member of his community; at one point, he even posed with First Lady Rosalynn Carter. Gacy's life growing up was difficult because his father was an alcoholic who beat his wife and son John and terrorized his daughters. Gacy never had his father's approval. In addition, when John was a child, he was accidentally struck in the head by a swing and experienced blackouts for five years until a blood clot was diagnosed and dissolved by medications. Gacy was executed on May 10, 1994.

Case 1 (mass murder) and Case 2 (serial murder) can be analyzed and categorized by fitting them into one or more of the theories developed to explain the phenomenon of multiple murder. The theories are developed by experts in the field who study mass and serial murderers.

1. If you are a forensic examiner called in to review either the remains of Andrea Yates's five children (Case 1: Mass Murder) or the 29 young men's decomposing bodies found under John Wayne Gacy's house (Case 2: Serial Killer), what steps would you take to determine causative factors of the case you have chosen?

2. Would you resort to textbook theories that are given from a sociological or psychological perspective? Why or why not? In addition, would you focus more on psychobiological or biochemical reasons behind the perpetrator's violent behaviour?

3. What, according to you, has more influence on a person's behavior, nature or nurture, and why?