Ever since it first premiered back in 1992, ‘Dateline NBC’ has been a staple for true-crime followers and the entirety of the newsmagazine genre. With its extensive archive of real-life mysteries and in-depth investigations that cover all aspects of a matter, it showcases what transpired and why in full detail. Thus, of course, its episode titled ‘A Killing in Cottonwood,’ profiling the May 2012 homicide of Karen Duenas, is no different. From doubts over the seemingly random attack to the disclosure of betrayal, this case has it all. And if you’re curious to know the details, we’ve got you covered.
How Did Karen Duenas Die?
As a life-long area resident of Redding, California, 51-years-old Karen Kay Duenas was serving as a college teacher and attending a nursing program when she suddenly passed away. Living in the suburbs of Cottonwood, she appeared to have an almost idyllic life with her husband of 33 years, Mark Duenas, and their five sons, but that changed on May 5, 2012. Karen used to be active in the community and her children’s lives, attending all sports events and supporting their every decision. So, when she was discovered unresponsive in the Duenas’ family home, no one could believe it.
At roughly 1 a.m. on that fateful day, Mark called 911 to report that he had just found his wife on her bed, cold and bloodied. Around that time, he’d also urged one of their sons to hurry next door, to their eldest’s, and raise the alarm that something terrible had happened to their mother. Once the emergency services arrived at the scene, they confirmed Karen’s demise. They couldn’t do anything to revive her. Her autopsy further revealed that she’d been stabbed multiple times, including a harrowing cut to her chest, which led to the loss of life. It was evident that she was murdered.
Who Killed Karen Duenas?
Because investigators marked a car speeding away just as they arrived at the scene and observed that the protective screen on the room’s window was slashed open, they initially assumed that Karen Duenas’ killing was a random attack. This theory strengthened once neighbors reported seeing a couple of strangers in the area that night during questionings. However, since Karen had no known enemies and there was no evidence of theft in their home, including a lack of ransacking, the suspicions changed. When leads dried up, Mark’s interrogation gave a breakthrough.
According to police records, Mark and his wife slept in different bedrooms because he snored and got up early in the morning. On May 5, he woke to strange noises, he said, and deeming them to be animals outside, he went downstairs to check. Once he came back without finding the source, Mark decided to see his wife, and that’s when he found her bloody. The officers subsequently inquired about their relationship, and Mark admitted to their troubles in the last year. After all, he’d begun an out-of-state and over-the-phone relationship with a woman in Idaho.
Confessing this fact, Mark revealed that they had known each other as teenagers, and he’d reconnected with her through Facebook. They texted back and forth in the months that ensued and shared images, which were all innocent, but they’d also said “I love you” three times. Karen found out about this through her husband’s billing records and confronted him, and he apologized. Yet, he continued the involvement via a secret phone until his girlfriend broke off all contact in January 2012. She’d told her husband and sent a letter expressing her regret to Karen.
Once all this came to light and probes to gather additional evidence were completed, Mark Duenas was apprehended and charged with first-degree murder four months after the fact. The authorities concluded that he slew his long-time wife to continue his association with the other woman. They also claimed that Karen threatened to divorce him, which made him reach his breaking point. Mark’s first trial was declared a mistrial, but his second was different.
With evidence including the assumed murder weapon and Mark’s clothing with traces of blood on it, along with testimonies implying that Karen was upset about her husband’s affair on the day she died, he was convicted in late 2013. The most vital piece of incriminating proof, though, was Mark’s initial 911 call, where it seemed like he confessed to the slaying. While the prosecution argued that his unclear first words were, “I gotta – I killed my wife. Shit. I mean, blood everywhere,” the defense declared that he said, “I gotta – I found my wife sick. I mean, blood everywhere.” The jury sided with the prosecution.
Read More: Where is Mark Duenas Now?