Somerset, PA (WBNG Binghamton) John DeSisti of Waverly died in state prison Monday morning, according to the Somerset County Coroner.
DeSisti, 76, died at SCI Laurel Highlands, where he was being held, according to Wallace Miller, Somerset County Coroner.
Miller would not provide a cause of death.
In December 2010, DeSisti was arrested and charged with two counts of homicide, along with other related charges in the deaths his cousin, Carol Keefe and her husband David.
The couple was found dead in their Athens Twp. home in Nov. 2006.
In July 2013, a judge declared DeSisti was not competent to stand trial.
DeSisti's lawyers argued that their client had dementia and at that time, said that he only had months to live.