Authorities are investigating after a Cook County Jail inmate died at a hospital after he was found unresponsive in his cell on Monday.

Michael O’Connor, 33, was housed in the jail’s Residential Treatment Unit, according to a statement from the Cook County sheriff’s office. The Cook County medical examiner’s office has not yet reached a finding on the cause or manner of death, a spokeswoman said.

Security and medical staff members with Cermak Health Services, which provides medical care to inmates, began lifesaving measures, but O’Connor was pronounced dead at Mount Sinai Hospital, the sheriff’s office said.

In a statement, the sheriff’s office said that no foul play is suspected but noted that the medical examiner’s office would make that determination. The Illinois State Police Public Integrity Task force is investigating.

O’Connor was awaiting trial on multiple felonies after he was arrested in June and accused of threatening a Chicago police officer and sending her explicit content, according to court documents.

He was held in jail on an $100,000 deposit bond that was issued shortly before cash bail was abolished in Illinois.

A police report alleges that O’Connor sent a female Chicago police officer pornographic images and videos of him exposing himself. He also sent her threatening text messages, the report alleges.

A judge in October ordered that O’Connor undergo a psychiatric examination and he was ordered into treatment at the jail, records show.

A hearing to determine whether O’Connor was fit to stand trial had been scheduled for Jan. 12.

At least 16 other Cook County Jail inmates have died in custody in 2023.