"Sleepwalking is slightly different from such a reflex reaction. Sleepwalkers seem attuned to their environment, and are seemingly goal-directed, but they are not completely conscious."
Sleepwalking has been used as a criminal defense since the 19th century, Morse said.
In 1846, Albert Tirrell became the first American to be acquitted on a sleepwalking defense after he was accused of murdering a prostitute and burning down her brothel.
In 2001, a jury acquitted Adam Kieczykowski, a self-proclaimed sleepwalker, after he was charged with burgling 10 dorm rooms at the University of Massachusetts at Amherst.
But victims' rights organizations see sleepwalking, particularly in instances of rape, as merely an excuse, and not a legitimate defense.
"This is just another way men are let off the hook and not made responsible for crimes committed against women," said Daisy Kler, spokesperson for the Canadian Association of Sexual Assault Centers. "Sleepwalking is used as an excuse, like, 'I was drunk or I was high.'"
"Neither Ecott nor Luedecke denied having sex with these women. Ecott knew he had a problem, but didn't take precautions. He didn't lock himself in his room, or avoid sleeping in a group of young girls."