The following definitions are applicable to this chapter:

1. "Intentionally." A person acts intentionally with respect to a result or to conduct described by a statute defining an offense when his conscious objective is to cause such result or to engage in such conduct.

2. "Knowingly." A person acts knowingly with respect to conduct or to a circumstance described by a statute defining an offense when he is aware that his conduct is of such nature or that such circumstance exists.

3. "Recklessly." A person acts recklessly with respect to a result or to a circumstance described by a statute defining an offense when he is aware of and consciously disregards a substantial and unjustifiable risk that such result will occur or that such circumstance exists. The risk must be of such nature and degree that disregard thereof constitutes a gross deviation from the standard of conduct that a reasonable person would observe in the situation. A person who creates such a risk but is unaware thereof solely by reason of voluntary intoxication also acts recklessly with respect thereto.

4. "Criminal negligence." A person acts with criminal negligence with respect to a result or to a circumstance described by a statute defining an offense when he fails to perceive a substantial and unjustifiable risk that such result will occur or that such circumstance exists. The risk must be of such nature and degree that the failure to perceive it constitutes a gross deviation from the standard of care that a reasonable person would observe in the situation.