A Houston man charged with murder in his wife's death admits to shooting her but contends that he isn’t fully responsible because he was sleepwalking at the time.

Raymond Lazarine, 67, went on trial this week in the December 2013 death of his wife, Deborah.

Raymond Lazarine told police he thought he was dreaming when he shot his wife, Deborah. Click2Houston

On the day of her death, Lazarine called his son just before noon and told him he had shot his wife, Houston police said. Deborah Lazarine had been shot six times, including in the head and back.

Raymond Lazarine was taken into custody and a weapon was recovered, but he later told police he thought he was dreaming when he shot his wife of 35 years, NBC Houston affiliate KPRC reports.

Now, his lawyers are presenting a sleepwalker defense in court, telling the jury that Lazarine did not purposefully kill his wife and a medical condition is to blame.

"Our position over here is this was a dream and it wasn't voluntary," Lazarine’s attorney, Feroz F. Merchant, said at the trial, according to KPRC. "We've had him evaluated, and obviously the experts are going to come by and say, 'Hey, we think he suffers from a medical condition where it's involuntary.'"

Retired Houston homicide detective Fil Waters, who was one of the initial investigators, said, "He mentioned something there that was more of an off-the-wall comment about, 'This is like a dream I wish I could wake up from,'" KPRC reported.

Lazarine’s son testified that his father had been under a psychiatrist’s care for over a decade, taking prescription drugs that he sometimes mixed with alcohol. Lazarine told police he had taken his medication the day of the shooting.