9 Factors to be considered for a sentence of death
prescribed by the Supreme Court in the case of
Norio Nagayama:
1) Nature of the crime (事件の性質)
For money, love, vengeance, pleasure, self defense, self-protection, etc...
2) Motive (動機 )
3) Degree of Cruelty 殺害方法の執拗（しつよう）性、残虐性
4) Consideration of the victims (結果の重大性（特に被害者の数）
Old, young, gangster types, mean or innocent, previous relationship to the defendant)
5) Feelings of the victims families. (被害感情)
6) Crime's impact on society. (社会的影響)
7) Age of the defendant. (被告の年齢)
8) Previous criminal record. (前科)
9) Post crime circumstances: defendant's attitude, factors that may make the death penalty unavoidable. (事件後の情状－－を総合考慮し、刑事責任が重大でやむを得ない場合に死刑が許されるとしている.)
The Supreme Court did not prescribe a mathematical model for weighing the above factors. I.E., five factors in favor of the death penalty does not necessarily mean that sentence should be imposed. The decision is certainly subjective.
Also, the parenthetical comments are JIADEP descriptions. As you can see some of the categories are not mutually exclusive. I (Michael Fox) am not exactly sure what #6 is exactly about..I would guess whether or not the crime shocked society, and whether issuing a sentence of life imprisonment would cause social concern, giving the impression that if such a crime can be committed and the defendant will have a second chance at freedom.