Man convicted in Johnson County case accused in Mount Pleasant prison attack

An inmate sentenced in a Johnson County sexual abuse case has been placed in segregation after attacking a female officer at the Mount Pleasant Correctional Facility early Monday, Iowa Department of Corrections officials confirm.

Antonio Mikhal Johnson, 24, is accused of stuffing a piece of clothing into a correctional officer's mouth and wrestling her to the floor during routine unit checks around 3 a.m.  today, officials said.

Two inmates helped pull Johnson off the officer, and she was able to activate an emergency alert to summon security staff. The Iowa Division of Criminal Investigation is investigating the incident.

Johnson is serving 10-year sentence for a charge of third-degree sex abuse at the Mount Pleasant facility following a 2008 conviction from Johnson County. Before the incident, he was tentatively set to be released in April 2012, according to Iowa Department of Corrections online records.