The 17-year-old youth arrested this week in Aizuwakamatsu, Fukushima Prefecture, on suspicion of killing his mother and cutting off her head "has admitted to the killing and recognized the gravity of the situation," his lawyers said Friday.
The state-appointed lawyers said they did not get a satisfactory explanation of why he killed her when they met with him earlier in the day.
The youth, whose name is being withheld because he is a minor, turned himself in to the Aizuwakamatsu Police Station on Tuesday morning with a bag containing the head, saying he had killed his mother. Police arrested him after they found the body and a severed arm in his apartment.
The lawyers said they had not decided whether to ask the court to order a psychiatric examination to determine the teen's mental capacity at the time of the murder.
They said he has eaten and slept while in custody and appeared calm when they met with him for an interview.
"His voice was soft. Otherwise, he looks like an ordinary high school student," one of the lawyers said.
The boy talked, sometimes with an expression that might be interpreted as pleased, about the trips he made with his family to a city in Fukushima Prefecture and the coast in Niigata Prefecture, and about his extracurricular activities, according to the lawyers.
Police have said he told them it did not matter whom he killed and that he had bought a saw in advance.