A Chicago resident and registered sex offender has been charged with threatening Illinois Attorney General Lisa Madigan.

Maurice Pennington Sr. was arrested in his home last night and charged with one count of threatening a public official.

Attorney General spokeswoman Natalie Bauer said Pennington is actually registered as a sex offender under the name Demetrious P. Moore.

“He’s involved in some litigation against the state, and earlier this week filed a brief in the 7th circuit court of appeals that contained threatening statements,” said Bauer.

The filing questions the constitutionality of the sex offender laws in Illinois and Bauer said it had a violent context. Pennington was convicted of criminal sexual abuse of a 14 year old victim for an incident that occurred in 2000 in Texas.