The murder of Kathy Wangler by her husband, Dr. Mark Wangler, will be detailed in the latest episode of Til Death Do Us Part on Investigation Discovery.
On September 4, 2006, officers with the Allen County Ohio Sheriff’s Office were dispatched to a home in Lima, Ohio, after receiving a 911 call from Mark claiming his carbon monoxide detector was going off and his wife was having a seizure.
Emergency first responders transported Kathy to Lima Memorial Hospital, where she was pronounced dead.
Mark, who worked as an anesthesiologist, told investigators that his gas water heater started leaking poisonous carbon monoxide into the home after it malfunctioned. He went on to say that he noticed something was amiss when he became disoriented and started vomiting. When he went upstairs to check on his wife, he wasn’t able to wake her up.
The following day, Dr. Diane Scala Barnett, a forensic pathologist with the Lucas County Coroner’s Office, performed an autopsy and determined that Kathy had been dead hours before Mark called 911 for help.
Police officials were skeptical of his story when they uncovered that there was no indication that his gas water heater had malfunctioned. They believed he pumped exhaust from an engine, that was located in the garage, into the bedroom where his wife was sleeping.
Mark wasn’t arrested until three years after his wife’s death. At that time, he was remarried and had moved on with his life.
In 2011, Mark pled not guilty to aggravated murder. Following a trial, a jury found him guilty.
He was sentenced to life in prison with the chance of parole after 25 years.
Mark appealed his conviction in 2013, claiming he wasn’t given a fair trial, but it was denied.
Til Death Do Us Part — While You Were Sleeping, airs at 10/9c on Investigation Discovery.