Walsh and Raine both deduce, for entirely different reasons, that there are two classes of violent criminals. Raine found the distinction in PET brain imagery. Walsh found a distinction between those who do and do not have incorrigibly corrupting backgrounds with imbalances in body chemistry usually being causal for the latter.




In 1984 a murder was apparently caused by an insecticide's interference with acetylcholine in the hypothalamus. The murderer worked for a lawn company. The insecticide he was applying has now been banned. See neurobiology class descriptions:   bio 1, bio 2 and ref.  
Garabedian was convicted: trial summary,   plea rejected
The case was recently reopened for trial and the poisoning plea was rejected by jurors.
In February 2009 Garabedian was convicted of first-degree murder.

More generally, there may be a link between MAOA and violence.



PBS video: The Violent Mind, episode 8

The normally docile Garabedian turned murder was working for a lawn company. He had been mixing and applying large quantities of insecticide not long before a sudden burst of rage and killing a customer.

Independently a researcher had noticed repeatable incidents of aggression in his cat after treatment for flees. It was the same insecticide, and the lawyer pursued the issue bringing in more analysis of mental effects by the chemical.


David Garabedian was a 22 yr old working for (Old Fox?) Lawn Company in early 1980s, Mother: Dolores
He was on trial in early 1984 in Cambridge Massachusetts
He killed Elleen Muldoon in March
Assistant District Attorney: Tom Reilly
Nancy Fernandez, reporter for NBC News
The insecticide Garagbedian was applying was Dursban 4E =? Carbaryl
He described the fumes as smelling like rotten eggs.
Symptoms he was having before the murder were:
  eye irritation, diarrhea, drooling, head aches, bad night mares, a fight with his sister
  (He was normally a calm non-aggressive guy.)
Garabedian was caught urinating, and that embarrassment caused high firing rate of acetylcholine in the hypothalamus

His attorney: Robert Mardirosian
Dr. David Bear, Vanderbuilt Universidy School of Medicine
Claud La Chenn, Professor at Harvard Medical School
  Chenn's cat became a very avid hunter after Dursban 4E powder treatment for fleas
Carbaryl is a cholenesterase inhibitor
cholinesterase clears acetylcholine



From trial summary:

HENNESSEY, C.J. The defendant was found guilty by a Superior Court jury of murder in the first degree on the basis of deliberately premeditated malice aforethought and extreme atrocity or cruelty...

On March 29, 1983, the date of the murder, the defendant was employed by the Old Fox Lawn Care Company of Chelmsford, which provided lawn care services to customers. The defendant's duties included "surveying" the lawns of prospective customers as well as applying liquid chemical treatments to customers' lawns. The defendant had worked for the company for about one month prior to the murder. During this period he was frequently exposed to lawn-care chemicals. He breathed in the chemical vapors, and at times the chemicals touched his skin. He had various symptoms of poor health which the jury could have found were caused by the chemicals. There was expert testimony that chemical intoxication was the cause of the defendant's violent conduct...

On March 29, 1983, the date of the murder, the defendant was employed by the Old Fox Lawn Care Company of Chelmsford, which provided lawn care services to customers. The defendant's duties included "surveying" the lawns of prospective customers as well as applying liquid chemical treatments to customers' lawns. The defendant had worked for the company for about one month prior to the murder. During this period he was frequently exposed to lawn-care chemicals. He breathed in the chemical vapors, and at times the chemicals touched his skin. He had various symptoms of poor health which the jury could have found were caused by the chemicals. There was expert testimony that chemical intoxication was the cause of the defendant's violent conduct.

The facts are established in part from the defendant's testimony. On March 29, 1983, the defendant left Old Fox to perform his first lawn survey at approximately 7:30 A.M. He then had various appointments throughout the day in several cities and towns, including Lincoln, Millis, and Shrewsbury. He testified that he had not eaten or urinated all day. At 4:30 P.M., the defendant performed a lawn survey at the home of Margaret Brassard in Townsend. Her only comments regarding the defendant's physical condition were that she found him to be very polite and a very clean-cut gentleman. He left the Brassard home at approximately 4:55 P.M.

The defendant then traveled to the Muldoon home on Fletcher Street in Dunstable. Upon arriving, he rang the doorbell and knocked on the door several times, but no one answered. He then proceeded to measure the yard and fill out his survey sheets. Because he believed no one was home, he walked to the left rear of the house and, facing the house, began to urinate on the grass. When he had almost finished, he noticed a woman standing toward his right on top of a hill looking down at him. She came upon him and castigated him for urinating. As soon as the defendant saw her he closed his zipper and apologized to her. He walked around a wall and up the hill to attempt to talk the woman out of her anger. She stated, "Well, I think I should call your boss." He continued to apologize and "tapped her on the arm" saying, "I'm really sorry you feel this way." The woman screamed and scratched the defendant on the face, drawing blood and leaving a cut. The defendant then grabbed the woman around the neck, strangling her manually. They were on top of a ledge and both fell to the ground. The woman was not moving. A tie string which the defendant had taken from his jacket earlier in the day was lying next to him, which he then used to strangle the woman again. He then picked up three large rocks, weighing forty-eight, forty-four, and twenty-two pounds, which he threw at the victim, hitting her face and head.