ONE USEFUL SENTENCE IS BETTER THAN A THOUSAND USELESS WORDS
Sahassam api ce vaca anattha padasamhita
Ekam gatha padam seyyo Yam sutva upasammati.
Better than a thousand utterances, comprising useless words, is one single beneficial utterance by hearing which one is calmed. 
Tambadathika who was a former thief had served the king as the public executioner for fifty-five years; and had just retired from that post. One day, he went to the river for a bath, intending to take some specially prepared food on his return home. As he was about to take the food, Venerable Sariputta, who had just arisen from sustained absorption in Concentration (jhana samapatti), stood at his door for almsfood. Seeing the monk, Tambadathika thought to himself, 'Throughout my life, I have been executing thieves; now I should offer this food to the monk.' So, he invited Sariputta to come in and respectfully offered the food.
After the meal, Sariputta taught him the Dhamma, but Tambadathika could not pay attention, because he was extremely disturbed as he recollected his past career as an executioner. This mental disturbance did not allow him to concentrate properly. Sariputta knew this, and in order to put him in a proper frame of mind, he asked Tambadathika tactfully whether he killed the thieves because he wished to kill them out of anger or hate, or simply because he was ordered to do so. Tambadathika answered that he was ordered to kill them by the king and that he had no ill will or wish to kill. 'If that is the case,' Sariputta asked, 'What wrong did you do?' Thus re-assured, his mind became calmer and he requested Sariputta to continue his sermon. As he listened to the Dhamma attentively, his mind became tranquil and he developed the virtues of patience and understanding. After the discourse, Tambadathika accompanied Sariputta for some distance and then returned home. On his way home he died due to an accident.
When the Buddha came to the congregation of the bhikkhus in the evening, they informed him about the death of Tambadathika. When asked where Tambadathika was reborn, the Buddha told them that although Tambadathika had committed evil deeds throughout his life, because he comprehended the Dhamma, he was reborn in the Tusita deva world. The bhikkhus wondered how such an evil-doer could have such great benefit after listening to the Dhamma just once. To them the Buddha said that the length of a discourse is of no consequence, for one single sentence of the Dhamma, correctly understood can produce much benefit.
*In this story we can see that the doing of evil and the bad effect that follows both happen in the mind. There is no external factor which determines the punishment. Although wilful killing in itself is wrong, Tambadathika's mind was free of guilt and direct responsibility although at first he was confused and overcome with doubt. When he listened to the Dhamma his mind was freed from many other defilements and he was reborn in a blissful state. This is because rebirth is determined by the state of mind at death. However, he is not free from the effect of killing even though he was not solely responsible for the act of killing. Although rebirth has taken place in theTusita devaworld due to his immediate goodkamma, the bad effects of his act of killing can follow later when his goodkammahas been all expended. This is the nature ofkamma. The only way to completely negate the effect ofkammais to attain Arahanthood (i.e. remove all residual mental defilements). This happened in the case of Angulimala. See Chapter XIII Story (6).