A Maryland inmate named Thursday as a “person of interest” in an 18-year-old homicide investigation was found dead in his cell about 11 hours after police described his standing in the case of Alison Thresher, according to police and prison officials.

Fernando Asturizaga, 51, was found at Western Correctional Institution in Cumberland, Md., about 8:45 p.m., police officials said.

Asturizaga was serving more than 100 years for sexually abusing Thresher’s young daughter over several years beginning in 1999.

He had been convicted after a 2012 trial.

On Thursday, Montgomery County police officials announced Asturizaga was a “person of interest” in the unsolved case of the girl’s mother, Alison Thresher, 45, who has been missing since 2000 and whose case has been investigated as a homicide.

Alison Thresher, who has been missing since 2000. (Montgomery County Police)

It was not immediately clear whether Asturizaga had seen accounts of the police news conference on television or knew that police intended to name him publicly.

Gerry Shields, a spokesman for the state’s Department of Public Safety and Correctional Services, provided few details about how Asturizaga died. “All indications were that it was a suicide, but the medical examiner’s office will make the final determination,” Shields said Friday.

“As with all inmate deaths, the department’s Internal Investigative Division is investigating along with Maryland State Police,” Shields said.

In the 1990s, Asturizaga taught Spanish and helped run a summer camp at Friends Community School in College Park. It was through school that he met Hannah Thresher, who was in the fourth grade, according to testimony at his sex abuse trial.

Asturizaga began babysitting Hannah, then 10, and her brother Sam, at the homes of their parents, who were divorcing. On Thursday, Hannah Thresher recounted that time as she appealed for the public’s help on any new information that might aid police in solving the case of her missing mother.

Beginning in about 1999, Alison Thresher raised concerns about the interest Asturizaga showed in her daughter.

“My mother had grown suspicious of him and knew that our relationship was inappropriate, which she made known to both him and others,” Hannah Thresher recalled Thursday. “I strongly denied it when questioned, as this man had carefully groomed me to do.”

Alison Thresher disappeared May 24, 2000. She was last known to be alive at her Bethesda apartment. Asturizaga continued to prey on Hannah Thresher after her mother disappeared, court records show.

The day on which Alison Thresher disappeared was supposed to mark a new start. She was set to start as a copy editor for The Washington Post.

She never arrived at work.

Her former husband, Jim Thresher, worked as a photographer at The Post.

On Thursday, police officials said Asturizaga had not been cooperating with their investigation.

Through Montgomery County police, the Thresher children declined to comment after Asturizaga’s death.

In her appeal for the public’s help Thursday, Hannah Thresher had said she and her brother have not been able to mourn over their mother’s body and never had a funeral for her.

“For us, it would mean everything, a chance to move on,” she said.