Complex sentence: Distraught, Russo decides to atone for his failure by coming clean to the press about his role in Underwood's schemes, but Frank stages his suicide, leaving him in a closed garage with his car running.
Split into simpler sentences: Distraught, Russo decides to make amends for his failure by coming clean to the press about his role in Underwood's schemes. As a result, Frank stages his suicide and leaves him in a closed garage with his car running.