Police believe suspect became tired from taking care of his wife
TokyoReporter
Victim found with wounds to head and chest
Victim's drink was laced with sleeping powder
Car flipped over near the entrance of Tokyu Driving School
Person is believed to have died at least 1 week before discovery
Suspect initially claimed he tried to save victim after blaze broke out
Suspect believed to have resold ¥20 million in tickets
Local committee upset report of incident delayed
Victims were drinking with group of 150 people at BBQ party
Boy suffered bruise, authorities say