Whoever commits culpable homicide not amounting to murder shall be punishable with (i) imprisonment for life or imprisonment of either description upto ten years, and shall also be liable to fine, if the act by which the death is caused is done with the intention of causing death, or of such bodily injury as is likely to cause death; or (ii) with imprisonment of either description upto ten years or fine or both, if the act is done with the knowledge that it is likely to cause death, but without any intention to cause death or to cause such bodily injury as is likely to cause death (Section 304).
This section contemplates two varieties of culpable homicide : (i) grave in which punishment may extend to imprisonment for life besides other alternative punishments, and (ii) simple in which the penalty of imprisonment for life cannot be awarded and the minimum penalty may be a fine only while fine in the grave form of the offence is not an alternative.
When in prosecution for offences of riot with murder it was found that since the accused persons wielded their lathis on the head of one of the victims they must have had knowledge that they were causing such bodily injuries to him as were likely to cause death, on such a finding they could be convicted only under Section 304, Part II and not under Section 304, Part I.
Section 303 provides that, whoever, being under sentence of imprisonment for life, commits murder shall be punished with death. Section 303, I.P.C. has been declared as unconstitutional by Supreme Court. Supreme Court observed that if life-convict commits murder Section 303 leaves no room for judicial discretion but only to punish with death.