1. Anyone who kills another person under any of the following circumstances shall be punished with imprisonment for fifteen to twenty-five years as a perpetrator of murder:
1. With treachery.
2. For a price, reward, or promise.
3. With cruelty, deliberately and inhumanely increasing the victim's suffering.
4. To facilitate the commission of another crime or to prevent its discovery.
2. When more than one of the circumstances provided for in the preceding paragraph is present in a murder, the sentence shall be imposed in its upper half.