Peterson's lack of emotion the hallmark of a psychopath, experts say

SAN FRANCISCO (AP) - Every day of his six-month murder trial, Scott Peterson marched into the courtroom with his head held high. He smiled at his family, took his seat and paid close attention, often whispering to his lawyers or taking notes.

Given a chance to defend himself in the murders of his pregnant wife Laci and their unborn son, the slick, handsome salesman with the megawatt smile had nothing to say.

His demeanor seemed to infuriate jurors and many trial watchers, who came to see Peterson as a manipulative, pathological liar with a grandiose sense of self and an inability to empathize.

Experts say this absence of emotion is the hallmark of a psychopath.

"They don't have the internal psychological structure to feel and relate to other people," forensic psychologist Reid Meloy said. "Sometimes they can imitate it, so they can fool other people, but there will come a point when they can't maintain it."

The times Peterson did display emotion were rare. He winced and put his head down when prosecutors showed autopsy photos of his wife and their fetus. He wiped tears from his eyes as his mother pleaded with jurors to spare his life. He wept softly when his sister-in-law recounted the first time she met his slain wife.

But passionate, angry and accusatory outbursts from Laci's family members when he was sentenced to death Wednesday didn't appear to faze him.

Meloy said that fits with the inability of psychopaths to form truly intimate bonds with others.

Such an absence of heartfelt emotion "gives the psychopath the ability at times to kill without remorse and to kill for reasons filled with banality," he explained. "Others' emotions of grief and rage and fury are like water off a duck's back."

That apparent lack of emotion raised investigators' suspicions in the first place, police and prosecutors said Thursday when they gave their first news conference since the trial began.

"His major concerns weren't Laci at the beginning of this case," explained Modesto Detective Al Brocchini. "He is very calm, cool, nonchalant, polite, arrogant. He thinks he's smarter than everybody."

Peterson's half sister, Anne Bird, said she thought his behavior was strange when he lived with her family during the investigation of Laci's disappearance.

"He is the most empty person. Everything he does seems to have been copied from someone else," she said.

When she last visited Peterson at the San Mateo County Jail in January, he seemed in utter denial as he talked about getting out of prison and leading a quiet, simple life somewhere, she said.

"I was wondering if he really understood the extremity of the whole thing. I think he's very bright, but he's kind of soulless. He's very empty. Somehow he's been lost."

The jurors who attended the sentencing Wednesday said they, too, saw something wrong with Peterson from the beginning.

"Scott came in with a great big smile on his face, laughing. It was just another day in paradise for Scott. Another day he had to go through the motions," juror Mike Belmessieri said. "He's on his way home, Scott figures. Well, guess what, Scotty?"

Juror Richelle Nice interjected: "San Quentin is your new home."

Psychopaths need greater stimulation than most other people in order to feel anything, Meloy said.

When Peterson arrived at California's death row at San Quentin State Prison early Thursday morning, he told a guard he was "too jazzed" to sleep.

"The most intense emotion he's derived through his whole trial was the excitement he received when he darkened the doors of San Quentin," Meloy said.