Complex sentence: Deciding he has to do something to stop the killer, he imitates Cartman's attempted flight so that he passes into a coma, and when he wakes up claims to have psychic powers and gives the police his original findings.
Split into simpler sentences: Deciding he has to do something to stop the killer, he imitates Cartman's attempted flight and is rendered comatose. When he wakes he claims to have psychic powers and gives the police his original findings.