What is Second-Degree Murder in Illinois?

Second-degree murder is similar to first-degree murder under the laws of Illinois. The State must still prove that the defendant killed the victim without legal justification and either intended to kill or cause great bodily harm, knew that such acts would cause death, or knew that such acts create a strong probability of death or great bodily harm.

What makes second-degree murder a lesser conviction that first-degree murder is that there must be mitigating factors present.  These factors are either categorized as “heat of passion” or based on an unreasonable belief that the acts leading to the death were justified.

Heat of Passion

The first set of mitigating circumstances that the law recognizes is stated as follows:

“At the time of the killing he or she is acting under a sudden and intense passion resulting from serious provocation by the individual killed or another whom the offender endeavors to kill, but he or she negligently or accidentally causes the death of the individual killed.”

Serious provocation is defined as conduct that is sufficient enough to excite an intense passion in a reasonable person.  What this requirement does is effectively prove that the defendant did not plan to kill, although the intent was there at the time of the killing.  Examples of this would be a husband who literally walks in on his wife cheating on him and ends up killing the adulterer in the heat of his jealous passion.

Unreasonable Justification

The second set of mitigating circumstances that the law recognizes is stated as follows:

“At the time of the killing he or she is believes the circumstances to be such that, if they existed, would justify or exonerate the killing under the principles state in Article 7 of this Code, but his or her belief is unreasonable.”

Article 7 includes such things as self-defense, defense of others, necessity, duress, or compulsion.  What this section means is that the defendant killed someone thinking they were protected under the laws.  The best example of this would be using more force than is legally allowed in self-defense.  While the law allows you to defend yourself, you cannot use deadly force to protect yourself when deadly force is not being used against you.

This set of mitigating factors also eliminates the premeditated nature of first-degree murder by making it circumstantial as to why the killing occurred, even though the intent to kill still existed.


Unlike first-degree murder, second-degree murder is not punishable by death or life imprisonment.  Classified as a Class 1 felony, the range of imprisonment for this crime is between 4 and 20 years.


Because the very definition of this crime requires that the killing be intentional, aside from complete innocence, the best defense against this crime would be a lack of intent.  This can be shown by successfully asserting those defenses listed in Article 7.  Aside from those already mentioned, insanity and involuntary intoxication may also be included.

Of course, a qualified Illinois Criminal Defense Attorney will craft the best defense.  An attorney will know and understand the nuances of the law and be able to best protect your rights and freedoms.

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