Complex sentence: Horatio shoots at the men after Speed is gunned down, killing one before tending to a fallen Speedle pulling a handkerchief out of his coat pocket to wipe the blood from his mouth.
Split into simpler sentences: Horatio shoots at the men after Speed is gunned down, killing one. Horatio then tends to a fallen Speedle pulling a handkerchief out of his coat pocket to wipe the blood from his mouth.