Simplify the following text for a Grade 11 native English-speaking person.
Original: His wife , Monique Olivier , denounced him following the conviction of Michelle Martin , wife of convicted child murderer Marc Dutroux for helping him with the crimes .
Simplified: His wife , Monique Olivier exposed him after hearing the news of another child murderer 's wife ( Michelle Martin , wife of Marc Dutroux ) being convicted .