Complex sentence: He identifies clues, investigates enigmas, and solves the riddle surrounding a mysterious stranger while the police and other adults overlook or dismiss the whole matter, which results in him and his friends several times solving real crimes including murder and kidnapping.
Split into simpler sentences: He identifies clues, investigates enigmas, and solves the riddle surrounding a mysterious stranger while the police and other adults overlook or dismiss the whole matter. He and his friends several times solve real crimes including murder and kidnapping.