(1) Except as provided in Section 210.3(1)(b), criminal homicide constitutes murder when:

  (a) it is committed purposely or knowingly; or

  (b) it is committed recklessly under circumstances manifesting extreme indifference to the value of human life.  Such recklessness and indifference are presumed if the actor is engaged or is an accomplice in the commission of, or an attempt to commit, or flight after committing or attempting to commit robbery, rape or deviate sexual intercourse by force or threat of force, arson, burglary, kidnapping or felonious escape.

 (2) Murder is a felony of the first degree [but a person convicted of murder may be sentenced to death, as provided in Section 210.6].