The law can't punish those who commit suicide, but it does punish those who assist in suicides, despite their having acted on their victims 'behalf--for criminal liability is not "made to order" but must be applied universally.
法律無法處罰自殺者，但處罰幫助自殺者，即使對方立下遺囑也不算數。因為刑事責任不能「約定」的。