Complex sentence: Fanni Kaplan shoots and seriously injures Bolshevik leader Vladimir Lenin, which along with the assassination of Bolshevik senior official Moisei Uritsky days earlier, prompts the decree for Red Terror.
Split into simpler sentences: Fanni Kaplan shoots and seriously injures Bolshevik leader Vladimir Lenin. This, along with the assassination of Bolshevik senior official Moisei Uritsky days earlier, prompts the decree for Red Terror.