He claimed he had no of anything else, but the girl said she’d woken to find him on top of her, raping her. She’d screamed and he’d told her to “be quiet” before getting up and walking away as if in a trance. He admitted that he’d committed the rape and apologized to the girl’s family, but they called the police.

At trial in 2007, Kenneth’s defense was that he suffered from a condition called “sexsomnia,” and had been asleep when he forced himself on the girl. He had not known what he was doing and was unable to control it. Therefore, he could not be found criminally responsible.

Kenneth’s girlfriend testified on his behalf, saying he often did things to her in bed while he was asleep and had no memory of it afterward. He had a reputation for among his buddies in the RAF. They’d even given him a “Night Rider” T-shirt as a joke.

Dr. Irshaad Ebrahim, from the London Sleep Centre, testified that and can be factors in this parasomnia. In addition, because Kenneth had recently flown from another country, he had symptoms of jetlag and sleep deprivation.

This testimony was persuasive. After only two hours, the jury returned a verdict of not guilty. The victim was stunned. This man had raped her and he’d admitted it, but he was “not guilty.”

In fact, there have been other such cases. A Toronto landscaper went through a similar ordeal. He, too, was drinking heavily at a summer croquet party in 2003 when he attempted to have with an unwilling partner. They had parted and had both fallen asleep on opposite ends of an L-shaped couch. The woman woke up to find him on top of her.

He’d removed her underwear and pulled up her skirt. She pushed him away and said he appeared to be confused. However, he’d been thinking clearly enough to put on a condom. She called the police and he was arrested.

At his trial, the landscaper claimed he’d been sleepwalking and had little memory of the incident. A expert testified on his behalf and, since the prosecutor failed to offer an expert to contradict this testimony, the jury acquitted. In 2008 an appeals court upheld the verdict.

Sexsomnia, also called behavioral disorder and “banditing,” is a rare but diagnosable form of automatism in which people carry out indecent sexual acts in their sleep. Among the activities of sexsomnia are vulgar talking, aggressive , loud moaning, and rape. Canadian researchers coined the term in a 2003 paper.

According to Dr. Carlos Schenck, a psychiatrist at the Minnesota Regional Sleep Disorders Center, there are eleven different types of sleep disorders that, collectively, are labeled sexsomnia. This phenomenon accounts for about 4 percent of adult sleep disorders and can cause a psychologically healthy person to engage in sexual activity while asleep, including forcing it on others.

Schenck did a search of 56 years’ worth of medical literature, studied medical texts, and gathered information through surveys. He found that males comprised the largest percentage of people who had such disorders, but it certainly affects females too.

Sufferers typically learn about what they were doing while only if a partner, roommate or victim tells them. Those at greatest risk often have suffered from other parasomnias, such as sleepwalking or night terrors. Some researchers think it is the result of a brain glitch, and is possibly related to epilepsy.

Automatism, especially in the case of sexual disorders, remains a controversial defense, and the results in a courtroom are as uneven as with any other psychological syndrome. Often, it depends on the expert’s ability to persuade. Some lawmakers have tried introducing bills to close what they call loopholes so that dangerous offenders, awake or asleep, are held accountable and treated.

Needless to say, victims of crimes in which a defense like sexsomnia inspires an acquittal feel that it violates the legal process and derails justice. However, experts insist that it is a legitimate medical disorder that deprives the sufferers of behavioral control.

One researcher who studied eleven cases a decade ago discovered that sexomnia responds to treatments for other sleep disorders, although some sleep medications seem to trigger it. The search for an appropriate remedy continues.