William Styler, the man who was convicted of killing an Aspen woman, was found dead in his cell Thursday morning.

Styler, 67, was a Denver anesthesiologist who pleaded guilty to second-degree murder of Nancy Pfister last year, according to CBS News. Prosecutors state that Styler killed Pfister, 57, in February 2014 with a hammer while she was asleep in bed. Her body was also tied up with an electrical cord and covered in plastic garbage bags. Prosecutors added that the motive for the grisly murder may have been over a financial argument.

Styler's death is an ongoing investigation by the authorities at Arrowhead Correctional Center in Canon City, where he was held behind bars serving a 20-year sentence. However, Fremont County Coroner Randy Keller said on Thursday that "at this point, it looks like a suicide."

Styler was initially charged along with his wify, Nancy, and another woman, Katherine Carpenter, a friend and former personal assistant of Pfister, with first-degree murder in the case, NBC News reported. However, all charges were dropped against the two women when Styler confessed to killing Pfister. 

Nancy Styler released a statement after being notified about her husband's death. "I hope people will remember him for the man he once was before his physical and mental illness took over his life," she said.