Video shows Richard Kirk being interrogated after killing wife while high on marijuana

DENVER -- Police have released video of a man being interrogated by detectives for the first time, just hours after he killed his wife while high on marijuana.

In the video, Richard Kirk appears impaired, even though a toxicology report taken that night detected just 2.3 nanograms of THC per milliliter of blood in his system. That's well below the state's limit for stoned driving at 5 nanograms.

"Honestly, I have no idea where I am right now. I don't know if I'm at the police station," Kirk told the detective.

It was either a man clearly confused or a criminal doing his best to convince police he was impaired.

The detective asked Kirk, "Do you understand each of these rights that I've read to you?"

After a pause, Kirk responded, "I was kind of spaced out."

And it was Kirk, not the detective, who asked the first question in the interview.

"Are you LDS?" Kirk asked when the detective walked in.

That set the tone for the rest of the interview. Kirk rambles about religion and has a difficult time staying focused. The interview was conducted less than two hours after Kirk killed the mother of his three young sons, Kristine Kirk.

However, Kirk doesn't answer any questions about what happened that night in April 2014.

"You won't believe what I've been through," he said.

Kirk would later claim his actions were controlled by THC, the psychoactive ingredient in marijuana.

He had eaten part of a marijuana gummy before he killed his wife. Kristine Kirk's family has filed a wrongful death lawsuit against the marijuana industry. It's the first lawsuit of its kind in the country.

"It's very like alcohol. If you were allowing every time someone got killed because someone ingested alcohol, you'd have thousands of wrongful death cases," said Dan Recht, a prominent criminal defense attorney in Denver.

Recht said the second-degree murder plea is an indication the case is a weak one, and he believes the family faces an uphill battle.

"These are not good lawsuits against alcohol producers and they won't be good lawsuits, I believe, against the producers of marijuana," he said.

Meanwhile, Richard Kirk is facing a battle of his own. He'll spend the next three decades behind bars.

"I'm jittery. I'm all worked up. I've been through a lot," he told detectives.