By Rusty Surette, NEWS 9

DUNCAN, Oklahoma -- A convicted felon hired as a substitute teacher in Stephens County is now charged with trying to having sex with a student.

Erwin Eugene Johnson, 24, was charged this week with two counts of lewd proposals to a child. Johnson was a sub at an alternative school in the Duncan School District.

"He was soliciting sex from a 15-year old girl and other girls," said District Attorney Bret Burns. "Other charges are possible at this time."

Johnson was convicted in a felony theft case in 2008.