Complex sentence: They get away with a lot of money, but Laurie has an uncontrollable homicidal streak that comes out when she is frightened; during the robbery, she kills her office manager and a security guard.
Split into simpler sentences: They get away with a lot of money, but Laurie has an uncontrollable homicidal streak that comes out when she is frightened. During the robbery, she kills her office manager and a security guard.