DIXON, IL - An inmate at the Dixon Correctional Center is facing rape and kidnapping charges after allegedly holding a prison staff member hostage for 25 hours last month.

John Spires, 50, was charged Tuesday with aggravated kidnapping, armed violence and two counts of aggravated criminal sexual assault.

According to the criminal complaint, Spires grabbed the female prison worker from a hallway in the prison's psychiatric unit and held her hostage in a storage area, using a “homemade knife with a blade about 8 inches long” to threaten her.

The May 11 incident set off a standoff between Spires and the Hostage Negotiation Team of the Illinois Department of Corrections. That standoff ended peacefully, and Spires has been transferred to the super-maximum prison facility in Tamms.

IDOC spokesman Derek Schnapp said the agency is still investigating the incident, and he declined to release any additional information.