Experts analyze killer impulse

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 to 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, 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 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 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.


"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 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 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 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.

"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."

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.

Charged with three counts of murder in Jan. 10, 2005, triple slaying. Charges dropped because of witness problems.

Found guilty of April 1, 2005, murder of Jamel St. Clair. Sentenced to life plus 20 years.