Complex sentence: Irving and Faurisson therefore invited Bill Armontrout, warden of the Missouri State Penitentiary, who agreed to testify and suggested they contact Fred A. Leuchter, a Bostonian execution equipment designer.
Split into simpler sentences: Irving and Faurisson therefore invited Bill Armontrout, warden of the Missouri State Penitentiary. He agreed to testify and suggested they also contact Fred A. Leuchter, a Bostonian execution equipment designer.