“Prosecution rests its case, Your Honor,” Arend said.
“Is the defense prepared to call its first witness?” Judge Economou asked.
“Yes, Your Honor. Defense calls Dr. Joseph Wu.”
Dr. Wu had a round face, a mustache, and a thick Asian accent. He wore half-moon glasses, which he looked over as they sat perched on his nose. He told the jury that his full name was Joseph Chang-Sang Wu. He was a graduate of Stanford, an expert on psychiatric disorders and brain scanning, the associate professor in residence in the department of psychiatry and human behavior at the University of California at Irvine’s Brain Imaging Center. He was a leading expert in using so-called PET scans to visualize brain function and/or activity. He’d published multiple articles on PET scans of neuropsychiatric conditions, and had received during the course of his career more than a million dollars in grants from the National Institutes of Health (NIH). He was a busy guy, teaching programs as an assistant professor, doing medical research, cutting-edge stuff. He’d been published many times.
“Articles?” Carolyn Schlemmer asked.
“Yes, and sometimes chapters in books.” He had written more than fifty peer-reviewed articles on PET scans and their usefulness regarding a variety of brain ailments, including Alzheimer’s, brain injuries, tumors, and epilepsy. In the leading book on psychiatry,
Kaplan and Sadock’s Synopsis of Psychiatry,
Dr. Wu wrote the chapter on functional brain imaging.
“You are a medical doctor, correct?”
“Yes.”
“Dr. Wu, perhaps you could explain for the jury just what a PET scan is.”
“Certainly,” Dr. Wu replied. He explained that PET stood for positron emission tomography, which referred to a nuclear medicine imaging technique that produced a three-dimensional image. The PET camera detected radiation from the emission of positrons. Point was, the resulting image not only showed the physiological makeup of the brain, but also revealed the
level of activity
in each portion of the brain.
“How are PET scans taken?”
As was true of other internal examination methods, a preparatory radioactive “tracer” was introduced into the body, usually via direct inoculation into the bloodstream.
The PET scan system indirectly emitted gamma rays in pairs that could be captured in an image. The tracer was allowed to remain in the body for a waiting period before the scan was taken. Flat images were captured at minutely varying depths within the target organ, and a computer subsequently assembled those slides into a 3-D image. The scan created a picture that didn’t just illustrate the size and density of a human organ, but also made sort of a map of its functional processes. You could tell which parts of the brain were functional and/or had structural differences from the norm.
“How long has this technology been around, Dr. Wu?”
“Approximately thirty years.”
“You could, for example, use a PET scan to find a brain tumor?”
“Yes.”
“Can a PET scan see even the smallest brain injury?”
“Often times, yes. It is quite precise.”
The technology could also be used to monitor persistent neurological symptoms. It could be used in conjunction with the treatment of post-concussive syndrome, as well as certain types of chronic headaches.
Any neurologist would tell you that severe head trauma could have an effect on behavior. This was well known even before scientists developed a way to photograph the inner brain. Brain damage could result in psychosis. Dementia. It could be completely debilitating. Some don’t recover, and the brain injury ends up affecting the rest of their lives. It was “fairly common” for brain injuries to result in patients who could no longer work for a living.
“Dr. Wu, when you first get your cases, is there already a belief that there is some abnormality? How do you get your cases?” Schlemmer asked.
“When cases are referred to me for imaging, it is usually the last step in a multistep process. PET scans are expensive, and are usually only done after patients have other types of clinical histories.”
“Are there instances where you do your PET scan and find the brain to be normal, so you do not testify?”
“That happens on occasion—although a vast majority of patients who are referred to me do have a positive PET scan.” That was, he explained, because patients he examined had a history of neurological abnormality. They did not represent a cross section of society.
Dr. Wu emphasized that PET scans would never be used as the sole criterion for diagnosis and treatment, unless the person was completely catatonic. Otherwise, the diagnosis would be based on a combination of a PET scan, personal interviews, and observations of social interaction.
“Where is the portion of the brain that controls behavior? Where is a man’s conscience, his ability to appreciate right from wrong?”
“Here, in the front,” Dr. Wu said, pointing at the center of his forehead.
“You took a PET scan of Michael King’s brain?”
“Yes.” The scan was made during August of 2008 at the National PET Scan Center. Conditions for making the scan were good, and there were no difficulties.
Dr. Wu was allowed to move from the witness stand so he could speak directly to the jury and operate a slide show from a laptop computer.
Schlemmer asked the difference between a PET scan and the more familiar MRI. Dr. Wu explained that the magnetic resonance imaging showed only structure. PET showed function. An MRI of a just-dead cadaver’s brain might be normal, while the PET scan would be able to determine that all brain function had ceased.
Asked to explain how PET scans were made, Dr. Wu likened the process to “
Star Trek
’s
USS Enterprise
starship engine.” He acknowledged that the show was fiction but said that the matter/antimatter science that the engine functioned on was a recognized principle of physics. Sugar was fuel for the brain. The PET scan determined function by measuring how much sugar was being burned in the brain.
A series of slides was shown: an Alzheimer’s patient versus a normal brain; a patient with a tumor versus normal; an epileptic’s brain versus normal; a traumatically injured brain versus normal.
A PET scan was shown that Dr. Wu identified as an image of the inside of Michael King’s brain. Dr. Wu testified that the PET scan clearly showed that the defendant had abnormalities in his brain—not so much in the back of the brain, but in the front. There was an abnormal lack of frontal-lobe activity. To put it in automotive terms, the front of King’s brain was not firing on all cylinders.
In a normal brain, the front burned as hot or hotter than the back. In King’s brain, the front was cooler than the back. This was consistent both with brain injury and schizophrenia.
There was a hole in the frontal lobe, a “divot.” The ratio of the back of the brain to the front was too high.
After a study of his medical history, it seemed a near certainty that this abnormality was damage caused by a snowmobile accident the defendant had when he was six. After the accident, Michael demonstrated a change in behavior. The description of the accident, which he’d gotten from King’s two brothers, matched the injury he was seeing on the PET scan. Put everything together and you had a clear picture of what happened to Michael and what the results were.
Such an injury, Dr. Wu said, might cause an inability to express emotions or demonstrate rational, logical behavior—as well as psychotic-like behaviors.
“Such as?”
“Paranoia, catatonia, the inability to think, impaired cognition, delusion, a blunted effect... .”
“What do you mean by a ‘blunted effect’?”
“We know that some people with this type of brain injury—patients will have little or no expression on their faces, as their brains have lost the ability to properly process emotion. These patients will demonstrate difficulty regulating their moods and will have a greater vulnerability to depression. These are all things likely to occur after someone has sustained a brain injury.”
Dr. Wu also said this type of brain injury could cause schizophrenia, which impaired ability to separate fantasy from reality.
Not every brain-injured patient was going to become schizophrenic, or psychotic, or anything else. But the
likelihood
of developing those mental problems increased with people who had injured frontal lobes.
Dr. Wu used the analogy of smokers. People who smoked cigarettes were far more likely to develop lung cancer than people who didn’t smoke—but that didn’t mean that all smokers developed cancer, or that all nonsmokers didn’t.
Studies had shown that Vietnam veterans were more likely to demonstrate aggressive behavior after their return to civilian life, but did that mean that all Vietnam vets were aggressive? Hardly.
People with frontal-lobe injuries were at a greater risk of behavioral difficulties, such as impulse control. A person who merely enjoyed gambling before an injury might find himself a compulsive gambler after the injury. What had really changed was his ability to tell himself no.
“Are symptoms that follow brain injuries constant and steady?”
“No, as a rule they are more episodic. They may be triggered by stress or some other factor.”
Another analogy: the brakes on a car. A patient with frontal-lobe damage might have trouble hitting the behavioral brakes, and might just go ahead and do something because he had the urge at that moment—he’d do it without properly considering the morality or the consequences of his actions.
Dr. Wu discussed specific witness statements he’d read and how they reenforced his testimony. It was a statement from Michael King’s ex-girlfriend, he felt, that best demonstrated the depth of the defendant’s paranoia. The ex said King “always thought someone was following him.” He’d nailed his windows shut, kept a handgun under his pillow. He was convinced there was a cop living across the street from him who was out to get him. On January 15, 2008, two days before the murder, the girlfriend reported that his paranoia was worse than usual, and she’d noticed that stress tended to make it worse.
According to one of the brothers’ statements, King had had difficulty distinguishing reality from fantasy starting at a very early age. When he was in the third grade, he reportedly chopped down several trees because he was fearful that there were witches in them. His brothers thought, even back then, that it was very odd that Michael would have gone to such lengths, to the grueling effort of chopping down trees at eight years old, because of a fantasy.
“Dr. Wu, do you recall the so-called chain saw incident?”
“Yes, when Mike was seventeen, he acted out a scene from a horror movie called
The Texas Chain Saw Massacre.
He took a real chain saw, started it, and chased family members around the house with it. It was almost as if he placed himself in the movie and had difficulty separating fantasy from reality.”
Throughout King’s life, there were repeated episodes in which King had difficulty regulating his impulses. At these times, witnesses said, his face was expressionless. When King was thirteen, he reportedly acted out a scene from a Bugs Bunny cartoon, shooting a bow and arrow at his brother. He even went so far as to say, “Say your prayers, rabbit,” as the character in the cartoon had, just before releasing the arrow in real life. There was always a connection between King’s aggressive behavior and the dull, blank expression on his face. The two went together. Once, when the defendant stole a car, he had the dull expression. Another time, he rode a motorcycle recklessly with no helmet—blank expression.
According to Dr. Wu’s sources, in December 2007, a couple of months before the murder, the blunted effect on King’s emotions regularly took on “catatonic-like proportions.” By that time, his symptoms, when at their worst, resembled those you might see in an invalid, a psychotic.
All of this eyewitness data was important to Dr. Wu because it helped him interpret what he was seeing when he looked at King’s PET scans.
“Did you receive information that there came a time when Mike King appeared to have blunted emotions all the time?”
“No, not all the time. Maybe with increased frequency. This is typical of episodes of catatonia. There were times when he could be loving.”
“Were there other examples of bizarre behavior in the reports you read?”
“Yes. His brother Rodney reported that one time, Mike came to a stoplight next to girls in a car and he began to act peculiarly. Later he had no sense of himself behaving strangely, but he did wonder why the girls in the car were staring at him.”
“When did you learn about Mike having severe headaches?”
“His brothers reported that ever since his childhood accident, he had suffered from loud buzzing in his head, and he felt frustration because he couldn’t turn it off.”
Dr. Wu said that King’s symptoms worsened in January 2008. Things went wrong in his life. He lost his girlfriend, declared bankruptcy, gave up custody of his son.
It was impossible to say if things went wrong because his symptoms were worse, or if his symptoms grew worse because things were going wrong. Most likely, both were true, and the two fed off one another.