Police in Himeji, Hyogo Prefecture, said Tuesday they were questioning four youths in connection with the burning death of a physically disabled, homeless man there last October.
Two of the youths, both 16, had already been in police custody on a separate allegation of extortion. They were quoted by police as saying they had been in a foul mood on the day in question and threw a Molotov cocktail at the man, who had been living with two other people on the riverbank in the city, knowing he would not be able to run away.
Investigators, reckoning the suspects are guilty of conscious negligence, said the boys were aware that because of his disability the victim would not be able to escape the flames and would die.
The two other teens being questioned for their involvement are aged 18 and 15.