Complex sentence: Without animosity, Larsen tells the Deputy that he will use his time in prison to plan another larger bank robbery that would be foolproof as Larsen feels that he was only caught by using a partner, the next time will be singlehanded.
Split into simpler sentences: Without animosity, Larsen tells the Deputy that he will use his time in prison to plan another larger bank robbery. This new robbery would be foolproof as Larsen feels that he was only caught by using a partner; the next time will be singlehanded.