A 68-year-old inmate in the Fairfax County jail, who was housed in the facility’s medical center, was found unresponsive Saturday night and later died at Inova Fairfax Hospital, sheriff’s officials said Sunday.

No cause of death was immediately available, but there were no signs that he had an altercation with anyone inside the jail, a sheriff’s spokesman said.

Paul Guida, 68, of the Falls Church area, had been in jail since Oct. 1 without bond on a charge of failure to appear in court, and also was charged with violating a protective order for a third time in 20 years, according to the sheriff’s office. He was immediately placed in the jail’s infirmary due to his medical conditions, which were not specified.

At 10:58 p.m. Saturday, a deputy found Guida unresponsive, the sheriff’s office said. Jail staff performed rescue procedures on him until paramedics arrived at 11:06 p.m., and Guida was taken to the hospital at 11:28 p.m. He was pronounced dead at 11:48 p.m., the sheriff’s office said.

The Fairfax County police homicide unit will investigate the death. Lucy Caldwell, a Fairfax police spokeswoman, said she did not know if an autopsy had been performed Sunday to determine cause and manner of death.

Lt. Tyler Corey of the sheriff’s office said Guida had “known, significant medical issues when he came into custody.” He said there was “no physical altercation that I’m aware of. He was not known to be a problem” prisoner, Corey said.

It is the second in-custody death in the Fairfax jail this year. In February, 37-year-old Natasha McKenna fell unconscious after a prolonged struggle with deputies who used a Taser on her four times while trying to transfer her from the Fairfax jail to Alexandria to receive mental health treatment. She died at Inova Fairfax Hospital five days later. The Virginia medical examiner later ruled McKenna’s death was due to “excited delirium associated with physical restraint including use of [the Taser].” The Fairfax prosecutor determined last month that no criminal charges would be filed against the deputies involved.