Rosalind Cartwright has defended a host of violent characters -- burglars, cat killers and even murderers -- some of whom still keep in touch each year with Christmas cards.
"They are all good people when you meet them, lovely human beings," said Cartwright, whose expertise isn't the law -- it's sleepwalking.
"Sleepwalkers can be violent," she said. "The upper frontal lobe, the most evolved part of the brain where moral teaching lives, is fast asleep."
Parasomnias, or sleep disorders, are some of the most misunderstood of all human behaviors, according to Cartwright, the former director of the sleep disorder center at Chicago's Rush University Medical Center.
Cartwright studied Kenneth Parks, one of the most famous somnambulists of all time, who killed his mother-in-law in 1987 and was the inspiration for a television movie with Hillary Swank, "The Sleepwalking Killing." Parks, a 23-year-old Toronto man with a wife and infant daughter, got in his car and drove 14 miles to the home of his in-laws. There, while still asleep, he stabbed to death the woman who called him the "gentle giant."
"He adored her," said Cartwright.
Afterward, Parks drove to the police station and declared, "I think I have killed some people...my hands." Later, doctors repaired several cut flexor tendons in his hands. A jury later found him not guilty.
"He still writes to me when he is in trouble," said Cartwright, who interviewed Parks in prison and later wrote about him in the journal Sleep. "He is the sweetest guy in the world."
What can go wrong when the brain is asleep is the topic of a chapter in Cartwright's latest book, "The 24-Hour Mind," due out in May. Filmmaker Allen Wolf also explores the topic in a fictional film inspired by Parks' case and others, "In My Sleep," which premieres in Los Angeles and New York this month.
A psychological thriller, the story opens when a man awakens in the middle of a cemetery, half-naked, with no idea how he got there.
To sleep experts, some of whom Wolf consulted for the medical dialogue, the narrative is not so far-fetched.
The topic of sleepwalking still fascinates more than a century after socialite Albert Jackson Tirrell was the first American to successfully use the sleepwalking defense after killing a Boston prostitute in 1846.
Sleepwalking is relatively common in childhood, but can be troublesome if it persists in adulthood.
About 15 to 20 percent of all children, both girls and boys, sleepwalk, according to the American Sleep Association. Usually it peaks around age 11 or 12 and rarely continues as they mature.
"Usually little kids get up and walk and you try to bring them back to bed and comfort them and make sure they are not wandering in to danger," said Cartwright. "But they can beat you up with their little fists."
Such was the case with Sue Sullivan's 13-year-old son Stephen, who has had always had night terrors.
"My son has been to 'walk the dog," and to "get the mail' and other interesting actions when sleeping," said the 46-year-old salesperson from Rochester, N.Y.
But one night it turned violent.
"I woke up to him screaming and punching me and pulling my hair," she said. "He was 'beating up the bad guy, Mom.' But in reality I was the one who he was beating up."
He has since been in a sleep study and is taking medication, which hasn't stopped the sleepwalking, but has stemmed the aggression.
About 2 percent of children, mostly boys, go on to be adult sleepwalkers, walking around, doing chores, eating and even climbing out windows and urinating in odd places.
Most Sleepwalkers Don't Kill
Though the sleepwalker remembers nothing, the partner often reports strange behaviors.
Daniel Houghton, a 28-year-old teacher from Montpelier, Vt., jumped up one night, insisting to his girlfriend that he had a relationship with Osama Bin Laden.
"I think it was near the election debates," said Houghton. "McCain had just called Obama, 'Osama,' by accident during one of the debates. Apparently I was digging around the sheets for Osama Bin Laden's business card. In my dream it had fallen out of my pocket."
He had no memory of the nocturnal event. "Maybe she dreamed the whole thing," Houghton said.
But others can be a danger to themselves or others, driving cars, having sex with strangers and even killing.
In 2007, Nick Walker, 26-year-old British Air Force mechanic whose military nickname was "night walker," for his sleepwalking habits, was found not guilty of raping a 15-year-old during one horrific sleepwalking bout.
Surprisingly most violent sleepwalking occurs in the earliest part of the sleep cycle, during deep sleep, before REM (rapid eye movement) and dreams occur.
In another rare condition mostly seen in the elderly, REM behavior disorder, sleepers can react in direct response to a dream and hurt their bedmates.
Some researchers say it is an early precursor to Parkinson's disease.
"One case I had would sit up in bed abruptly, telling his wife he thought there was an anaconda in his bed," said Cartwright. "He told her, 'I'll grab the head, you grab the tail.' He thought he was protecting her."
In both REM and non-REM sleepwalking, eyes are wide open and sleepers are difficult to wake.
Usually, a sleepwalking session ends abruptly, leaving the person confused and disoriented upon waking, with no memory of the event.
Researchers say there is a genetic basis to sleepwalking -- children whose parents are sleepwalkers are two to three times more likely to go on to exhibit the same behavior.
The "architecture" of sleep looks like a skyline, according to Cartwright. As the brain begins to shut down all visual and audio input, the muscles relax and breathing is progressively slower and deeper.
In about 20 minutes the body is in deep sleep with the highest amplitude and slowest brain waves. It is during this time that walking and talking are most likely to occur. In children, those delta waves are accompanied by growth hormone.
"You are really out of it," said Cartwright.
But gradually, the deep cycle decreases and the waves have less amplitude, and after 30 minutes, the sleeper moves into the REM or rapid eye movement phase.
REM is characterized by a sudden and dramatic loss of muscle tone where the person is essentially paralyzed, except for the eyes, which dart like "ping-pong balls," breathing, and in men, erections.
It is also associated with dreaming and the blood pressure and breathing can be erratic.
Throughout the night, the brain moves between those two phases in 90-minute cycles, with deep sleep becoming shorter and REM periods longer.
The last REM period of the night comes six to seven hours later and it's "very long, very vivid, lots of color, lots of drama and lots of emotion," said Cartwright. "You go from a short preview of the coming attraction to a biggie and it goes from what is currently on your mind to long-term memories."
But the most heinous crimes tend to occur in non-REM parasomnias.
Instead of responding to dream narratives, these sleepwalkers do something peculiar, like go into the kitchen and make crazy food combinations that they would never eat when awake, like a "cold bacon and chocolate bar sandwich," according to Cartwright, "or they wander off in the car and crash it up."
Most violent sleepwalkers are men, but Cartwright treated one woman who killed her cat in her sleep. "She was crazy about that cat," she said of her patient.
Standard treatments include the medication clonazepam, which relaxes the muscles during sleep. Other doctors say hypnosis or stress-relieving interventions can work in some cases.
Cartwright successfully treated an athletic director at a local college who was charged with home invasion and intent to rape the teenager.
He often kept an eye on two neighbors' homes and did so before going to sleep one night. But an hour later, he got up sleepwalking, thinking he saw lights on in another house across the street.
Asleep, he walked into the unlocked home.
"He wandered into the bedroom where the teenage daughter was asleep with her boyfriend," said Cartwright. "She said that he touched her on her thigh and it woke her and she screamed.
"He was very confused, partially asleep and partially awake," she said. The girl recognized the neighbor and made sure he got home safely. But her mother, who had been away that night, reported the "crime."
The man was arrested on five felonies, but Cartwright's testimony helped to have the case dismissed.
"He was a lovely guy, just as nice a person as you would want to meet," she said. "He didn't hurt anyone."
Another purported sleepwalker she defended was not so lucky.
Scott Falater Stabs Wife in Sleep
In 1999, Scott Falater of Arizona was found guilty of stabbing his wife 44 times. Though he never denied killing his wife, Yarmilla, Falater said in his defense that he had a history of sleepwalking.
Falater's neighbor testified that he watched over his backyard fence as the father of two went inside his house to wash his hands, ordered his dog to lie down, then rolled his wife's body into the pool and held her head under water.
He had been trying to fix a faulty swimming pool pump, and defense lawyers suggested his wife may have interrupted him while he was trying again to fix the pump in his sleep, triggering a violent reaction.
"He had been under a lot of pressure," said Cartwright said. "The cops woke him up with the noise. He jumped up and thought there was an invader and rushed down stairs. When they asked him how many people were in the house, he said 'four,' two kids and himself and his wife. He didn't know she was dead."
Cartwright, who wrote up the case in a 2004 issue of the American Journal of Psychiatry, said she is still convinced he was innocent.
One of the misconceptions about sleepwalking is that somnambulists stumble and fall, but according to Cartwright, they have all their motor skills.
"They are very good at navigating space," she said. "They can go up and down stairs and drive a car. They can navigate in the world, but the face recognition is off."
And that is precisely why these sleepwalkers can murder their cats and wives, because their brains don't know their victims.
And in addition to being "nice people" during their waking hours, sleepwalkers like Falater, have one other trait in common.
"They are overly meticulous, maybe a little bit OCD [obsessive-compulsive disorder]," said Cartwright. "They are doing something good, but then when someone stops them, they turn violent."
If you or a loved one experience sleepwalking, doctors suggest finding a sleep clinic to determine the extent of the parasomnia. Specialists can recommend stress-reduction techniques and medications that can help the disorder.
You can find help at these Web sites: Sleep Health Centers and at the Rush University Medical Center Sleep Disorders Service and Research Center.