WICHITA, Kan. (AP) — Authorities say a 24-year-old inmate of the Sedgwick County Adult Detention Facility has died of an unknown cause.

The sheriff’s office says in a news release that the Antonio Bell was found around 10:15 a.m. unresponsive in his cell. Both onsite medical staff and emergency responders were unable to resuscitate him. He was pronounced dead at 10:55 a.m.

Officials say the death will be investigated by the Kansas Bureau of Investigation and the sheriff’s office.

He was booked into the jail on Sept. 30, 2013 on murder charges.