SB 6.1.68

tata enaṁ daṇḍa-pāṇeḥ
 sakāśaṁ kṛta-kilbiṣam
neṣyāmo ’kṛta-nirveśaṁ
 yatra daṇḍena śuddhyati
Word for word: 
tataḥ — therefore; enam — him; daṇḍa-pāṇeḥ — of Yamarāja, who is authorized to punish; sakāśam — in the presence; kṛta-kilbiṣam — who has regularly committed all sinful activities; neṣyāmaḥ — we shall take; akṛta-nirveśam — who has not undergone atonement; yatra — where; daṇḍena — by punishment; śuddhyati — he will be purified.
Translation: 
This man Ajāmila did not undergo atonement. Therefore because of his sinful life, we must take him into the presence of Yamarāja for punishment. There, according to the extent of his sinful acts, he will be punished and thus purified.
Purport: 

The Viṣṇudūtas had forbidden the Yamadūtas to take Ajāmila to Yamarāja, and therefore the Yamadūtas explained that taking such a man to Yamarāja was appropriate. Since Ajāmila had not undergone atonement for his sinful acts, he was to be taken to Yamarāja to be purified. When a man commits murder he becomes sinful, and therefore he also must be killed; otherwise after death he must suffer many sinful reactions. Similarly, punishment by Yamarāja is a process of purification for the most abominable sinful persons. Therefore the Yamadūtas requested the Viṣṇudūtas not to obstruct their taking Ajāmila to Yamarāja.

Thus end the Bhaktivedanta purports of the Sixth Canto, First Chapter, of the Śrīmad-Bhāgavatam, entitled “The History of the Life of Ajāmila.”