manu smriti (M.S.) chapter 8 talks about offences and punishments. Here are a few quotes.
M.S. 8.344. A king who desires to gain the throne of Indra and imperishable eternal fame, shall not, even for a moment, neglect (to punish) the man who commits violence.
M.S. 8.345. He who commits violence must be considered as the worst offender, (more wicked) than a defamer, than a thief, and than he who injures (another) with a staff.
M.S. 8.346. But that king who pardons the perpetrator of violence quickly perishes and incurs hatred.
M.S. 8.347. Neither for friendship's sake, nor for the sake of great lucre, must a king let go perpetrators of violence, who cause terror to all creatures.
M.S. 8.348. Twice-born men (those who have upnayana-samskAra, thread wearing ceremony) may take up arms when (they are) hindered (in the fulfilment of their duties, when destruction (threatens) the twice-born castes (varna) in (evil) times,
M.S. 8.349. In their own defence, in a strife for the fees of officiating priests, and in order to protect women and Brahmanas; he who (under such circumstances) kills in the cause of right, commits no sin.
M.S. 8.350. One may slay without hesitation an assassin who approaches (with murderous intent), whether (he be one's) teacher, a child or an aged man, or a Brahmana deeply versed in the Vedas.
M.S. 8.351. By killing an assassin the slayer incurs no guilt, whether (he does it) publicly or secretly; in that case fury recoils upon fury.