This document summarizes research into the biological and environmental factors that may contribute to violent criminal behavior. It discusses theories that genetics, brain chemistry, childhood abuse/neglect, and environmental stressors can increase risks of violence by impacting impulse control and stress response. However, experts say causes are complex with no single factor determining violence. The document also profiles the criminal history and background of Corey McMillon, who was convicted of murder, noting he exhibited several risk factors like abusive upbringing but some people can overcome such factors through support systems.

1. Experts analyze killer impulse
Scientists try to link biology, lifestyles with criminal acts
Confronting Crime
The Battle For Baltimore's Future
October 07, 2007|By Stephanie Desmon | Stephanie Desmon,
Sun reporter
Corey McMillon was angry. The teen in the camouflage
sneakers had disrespected him.
One of McMillon's buddies had asked 17-year-old Jamel
Jermaine St. Clair for $5, and Jamel had complied. Then
McMillon asked for $1. This time, Jamel said no. A simple no
too many, a slap in the face to McMillon.
He left, got his 9 mm semiautomatic handgun and confronted
Jamel on a desolate East Baltimore street. After McMillon
emptied Jamel's pockets, the teen turned and started to run.
McMillon shot him, then shot again and again and again.
"He was going to teach him a lesson," Tonya M. LaPolla, an
assistant state's attorney, would go on to tell a jury. "As he
approached the victim with his gun, Mr. St. Clair disrespected
him only one more time by running, and you don't run on Corey
Mac. Not only did he take his money, he took his life."
For decades, scientists have studied just what makes someone
take a life, cross the line from angry person to violent killer.
Baltimore has many Corey McMillons who kill brazenly,

2. without remorse. Are they born with something broken or
missing in their brains - impulse control, perhaps, or a
conscience? What's the influence of their environment, of
abusive parents, of dangerous neighborhoods, of violent video
games?
"The question of why we as human beings are violent is one of
the great unanswered questions about us," said Dr. Debra
Niehoff, a Johns Hopkins-trained neurobiologist and author of
the book The Biology of Violence: How Understanding the
Brain, Behavior, and Environment Can Break the Vicious Circle
of Aggression.
Humans are born with the capacity for aggression for survival
purposes, an evolutionary need to be able to face down attack
from wild animals, or from others invading their territory. "You
have to be able to defend yourself," said Dr. Allan Siegel of the
New Jersey Medical School, who has studied the neurobiology
of aggression and rage for the past 40 years.
As they strive to learn more about the underpinnings of violent
behavior, some scientists are researching genetic variations that
may be present in those who are prone to violence. In one study,
researchers discovered that the same variation in one gene
seemed to be found in most of the study subjects who had arrest
records.
Other scientists are looking at the brain's neurochemistry to see
whether long-term exposure to dangerous situations or abuse
throws off the fight-or-flight response system, causing violent
overreaction to minor provocations.
Meanwhile, MRI technology is allowing researchers to probe
the brain noninvasively, scanning to determine how it responds
when threatened. Using these techniques, they say they hope to
learn, among other things, why one person flies into a rage

3. when another walks away from the same situation. The goal is
to someday prevent violence before it occurs.
Still, at this point, said Siegel, "you can't say, `This guy's going
to shoot somebody.' We're a long way from that level."
Hard life, hard crime
If researchers were to look at the life of Corey McMillon, they
would find affirmation for some of their theories. But they
would still encounter some things they could not explain.
When McMillon killed Jamel St. Clair in April 2005, he was 29,
ancient by the standards of criminal life on Baltimore streets.
By he had done two stretches in prison, the first stemming from
a guilty plea for three counts of robbery with a deadly weapon
and drug possession in 1995, an incident in which all three
victims were shot. That episode took place the day after
McMillon was accused of shooting a former elementary school
classmate. Prosecutors didn't pursue the case, apparently to
focus on the more serious crime.
He got out of prison in 2000, only to land quickly back behind
bars for violating his probation with another drug charge. In
September 2004, he was released again.
By December, according to allegations in court documents,
McMillon was already re-immersed in a culture of guns and
drugs. In the next five months, he would be accused of shooting
the same elementary school classmate again as well as a
bystander (a jury found him not guilty). He would be implicated
in a brutal triple slaying at a halfway house in Remington in
January, though those charges were later dropped because of
witness problems. And he would be accused - and later

4. convicted - of gunning down Jamel St. Clair.
"I think Corey Mac's been a killer for years," said LaPolla, the
prosecutor, in a recent interview. "He was just lucky he hadn't
killed someone before. I'm not inclined to give someone points
for bad aim."
Many warning signs were there from a young age, according to
court documents. His father spent most of his life in prison.
When he was out, he was abusive. His mother was a drug addict
who mostly raised him on her own. He started drinking and
smoking marijuana when he was 13, tried heroin at 14. He
dropped out of Patterson Park High School at 16.
There were signs, though, that McMillon had people who cared
for him. When he was 6, his mother had him evaluated by a
therapist because she believed he had attention deficit disorder.
When he was 13, she sent him again, this time for the rebellious
behavior he was exhibiting.
Once McMillon was out of prison in 2004, LaPolla said, it was
time for him to mark his territory. He'd been gone a long time,
and the faces had changed. According to the report of an
investigator who interviewed McMillon before his sentencing in
2006, McMillon had low self-esteem and self-worth and
"needed to attempt to prove himself."
If he was going to get any respect, he would have to demand it -
at gunpoint if necessary.
"I think most of the time it is done so they'll be like the big man
on campus, tough in the street," said Jane Loving, an
experienced defense attorney who was assigned to the McMillon
case. "They want respect for having killed somebody.

5. "Unfortunately, there are areas of our society where instead of
being ostracized because you committed a murder, they seem to
be embraced."
Risk factors
So what makes someone pull that trigger? The debate, like many
that delve into human behavior, is often framed in the simplistic
terms of nature vs. nurture. That is, some of our psychological
makeup can be traced to genes and biology, while other parts
come from our environment, our experiences.
Most experts agree the answer lies somewhere in the middle.
"There's often a tendency to try to explain their behavior with a
simple solution," said Dr. David DeMatteo, a forensic
psychologist at Drexel University in Philadelphia. "We say a
bad upbringing or violence on television or, in the case of
[serial killer] Ted Bundy, exposure to pornography. But
armchair analysis fails under scrutiny.
"How many children are exposed to violence on television or
pornography that don't end up as killers? You have a lot of kids
with these behaviors, and very few actually progress to do
something very serious. ... We have not shown remarkable
success in determining who will be violent."
Some killers are clearly insane, driven to murder because of
inherited psychiatric disorders. Some are just prone to violence,
to rage, to being unable to control their impulses. Some are born
just a little bit more difficult to discipline than others. Some get
a rush from committing crime, are seduced by it in a sense.
Others, though, have it tough as they grow up in poor
neighborhoods with broken families, where lead paint is

6. prevalent, where delinquency is common and often contagious.
They are exposed to crime or drugs or other situations that can
go south in a hurry.
But these are just risk factors.
"People are not born violent," said Niehoff, the author. "What
they are born is vulnerable."
Said Dr. John M. MacDonald, a University of Pennsylvania
criminologist: "These are markers but not causes of homicide. If
you eat a really poor diet, it doesn't mean you'll die of a heart
attack. It just increases the risk.
"Out of that entire group of kids, only a small fraction of them
will become predators."
Some actually have "bad brain chemistry," said Siegel, the
neurology and neuroscience professor. That could be the result
of a number of different forms of damage, from fetal alcohol
syndrome to physical damage from a violent childhood to lead
paint poisoning. "In a sense it's not their fault, like Parkinson's
disease," he said. But usually that isn't the case.
Neuroscientists still don't know enough about what impulses are
transmitted in the brain during a violent act. With the use of
advanced brain scanning technology, they hope to learn exactly
how different neurons are linked with the expression of rage.
Looking at an MRI of a "street criminal," Siegel said, would
probably not show a change in the pattern of brain activity.
Serious violence will show something else. But what it all
means is still out there to be discovered, he said.
The practical application of this is to search for a treatment.
The brains of those prone to what Niehoff called "hothead

7. violence" look similar to those who suffer from depression and
post-traumatic stress disorder, meaning that they have a
decreased volume in part of the brain that is important in the
regulation of stress responses. This means some of that behavior
can be treated with medications such as Paxil and Prozac, she
said.
But some criminals are very different. They don't respond to
stress. Their arousal systems are so low that they are looking
"for more and more thrills to prove the world isn't just this flat,
boring place," Niehoff said.
This anti-social behavior is very difficult to treat, she said.
"People have thrown every drug in the book at it without
success," she said. Confronting these tendencies early on - when
it's evident a child doesn't understand rules and doesn't respond
to negative consequences may be the only thing that works. At
15 or 16, she said, it's just too late.
Some researchers say they believe many impulses of rage and
aggression can be controlled psychologically through good
parenting, mentoring, even therapy. Most people take a situation
that makes them angry, think twice about it and don't react with
brutality. For some, religion plays a role. "If a person knows
there's a higher authority looking over them, they'll think twice
about doing something," Siegel said.
Words like sociopath and psychopath are tossed around in
conversation, interchangeable ways of describing people who
use manipulation, intimidation and violence to get their way,
without any regard for the feelings of others.
What makes sociopaths and psychopaths different from standard
criminals is how they feel about what they have done, experts

8. said. For a standard criminal, "a lot of times they feel bad about
it," DeMatteo said. "They rationalize. But if someone is truly
psychopathic, they can commit horrendous acts and not feel
remorse. It allows them to engage in these behaviors unchecked.
"They don't have this inner voice saying, `Hey, maybe you
shouldn't do this.'"
As Niehoff said, "Their give-a-damn is busted."
McMillon never showed any contrition for the crimes he was
linked with, contending that he wasn't even involved in the
many acts where he was charged. "I've never seen any
indication that he felt the least bit sorry for anything he had
done," the prosecutor said.
"Corey maintained he didn't do any of it, but I don't think that's
true," said Loving, his former attorney. "I see he definitely had
no remorse."
Life plus 20 years
Judge Wanda Keyes Heard presided over McMillon's trial in the
summer of 2006. McMillon did not speak for himself at the
trial. No one from his family was there. His mother would not
comment when reached for this article.
After a jury found McMillon guilty of murder - and of a brazen
escape from Mercy Hospital in October 2005 after he was sent
there from jail with an ulcer - Heard sentenced him to life plus
20 years. The verdict is under appeal.
She had no sympathy for what society or circumstance may have
done to McMillon. She chastised him for choosing to be a
violent man, saying many others before him had been abused or
been exposed to drugs but had chosen to live clean.

9. "These facts are awful," Heard told McMillon and the
courtroom. "It's called coldblooded murder. That's what it's
called. ...
"You say that the reason for Mr. McMillon's bad behavior is the
community and the society that has turned its back on him, but
he has had family members who have been willing to step up.
Mr. McMillon has chosen not to. I know him to be an intelligent
man. I watched him during the trial. ...
"Why he has chosen this as his life I don't know, but I will
protect the community outside of the bars."
[email protected]
McMillon's record
History of Corey McMillon's criminal charges and convictions
Accused of shooting elementary school classmate on Oct. 23,
1995. Charges not pursued.
Guilty plea in robbery in which three people were shot on Oct.
24, 1995. Sentenced to six years, with part of sentence
suspended.
In 2000, violates probation with drug possession charge,
returned to prison.
Charged with Dec. 4, 2004, shooting of same elementary school
classmate, as well as a bystander. Jury later finds him not
guilty.