The Prophet (PBUH) would never rule against the defendant without admission or evidence

“I was sitting with the Prophet of Allah, sallallaahu ‘alayhi wa sallam, when a man came pulling a man with a braided rein, saying: ‘O Messenger of Allah, this person killed my brother.’ The Messenger of Allah, sallallaahu ‘alayhi wa sallam, said: ‘Did you kill him?’ The man said: ‘If he does not admit it, I will prove that he did, with evidence.’ Then the defendant said: ‘Yes, I killed him.’ The Prophet of Allah, sallallaahu ‘alayhi wa sallam, said: ‘How did you kill him?’ He said: ‘We were collecting leaves from a tree, and he cursed me, and made me angry. So I hit with an axe on his head and  killed him.’ The Prophet of Allah, sallallaahu ‘alayhi wa sallam, said to him: ‘Do you have anything to give on your own behalf [as blood money].’ He said: ‘I have no money beside my clothes and my axe.’ He, sallallaahu ‘alayhi wa sallam, said: ‘Do you think your tribe will pay on your behalf?’ He said: ‘I am too insignificant in the eyes of my people than for them to pay ransom for me.’ The Messenger of Allah, sallallaahu ‘alayhi wa sallam, then threw the ropes towards the person demanding the ruling, and said ‘Take your fellow.’ The man went with him, and when he turned away, the Messenger of Allah, sallallaahu ‘alayhi wa sallam, said: ‘If he kills him, then he is the same as him.’ Then the man returned, and said: ‘O Messenger of Allah, I have been informed that you said: ‘If he kills him, then he is the same as him,’ but I took him according to your order. At that, the Messenger of Allah, sallallaahu ‘alayhi wa sallam, said: ‘Do you not want him to take the burden of your sin and that of your brother?’ He said: ‘O Allah’s Prophet, yes.’ He, sallallaahu ‘alayhi wa sallam, said: ‘Then it shall be so,’ and the man threw the rope and reins, and let him go.”