Complex sentence: That night, Callahan runs into an old friend of his, also a motorcycle officer, Charlie McCoy (Mitch Ryan), who has recently divorced his wife and has become mentally unstable, and states that being a vigilante is the only way to stop crime.
Split into simpler sentences: That night, Callahan runs into an old friend of his, also a motorcycle officer, Charlie McCoy (Mitch Ryan), who has recently divorced his wife and has become mentally unstable. McCoy states that being a vigilante is the only way to stop crime.