NASHVILLE, Tenn. (AP) — Tennessee death row inmate Stephen Hugueley has died three days after the state filed a motion to set his execution date.

Attorney Amy Harwell said she received a call just before 6 a.m. Friday from a Tennessee Department of Correction chaplain notifying her of Hugueley’s death.

“He had been suicidal for years,” Harwell said, “But TDOC is telling me they do not think it was suicide.”

Hugueley was sentenced to death in 2003 for fatally stabbing prison counselor Delbert Steed at the Hardeman County Correctional Complex the previous year.

Hugueley, 53, had already been given a life sentence in August 1986 after he was convicted of shooting his mother, Rachel Waller of Dyer County, with a shotgun and dumping her body into the Forked Deer River.

In 1991, while Hugueley was an inmate at the West Tennessee High Security Prison near Henning, he killed an inmate. Six years later, Hugueley stabbed another inmate at the state’s maximum security prison at Brushy Mountain. Hugueley was later moved to the Riverbend Maximum Security Institution in Nashville.

The Tennessee Department of Correction did not immediately have a statement about his death.

Harwell issued a statement about Hugueley’s death, saying he “entered the Tennessee Department of Correction as a profoundly damaged individual who from his 12th birthday to today spent less than two years outside of an institutional setting.”

He spent the last 18 years in solitary confinement “where he had severely limited interaction with other humans and was systematically denied access to treatment and basic health care,” Harwell said. “Years of this kind of abuse took a tremendous physical and mental toll upon Stephen. That Stephen withstood this treatment for so long is a testament to the strength of his spirit.”