Killing someone is the most grievous offense one person can commit against another. At the same time, not all homicides are equal in the eyes of the law.

Some are considered murder, which can be punishable by life imprisonment in Illinois, while others are considered manslaughter, which can carry a prison term typically under 10 years. Chicago is no stranger to either of these, unfortunately.

What is the difference? The element of intent.

Murder is defined as the intentional killing of the victim, while homicide refers to the reckless and/or unintentional killing of the victim.

The prosecution will examine the evidence to determine which charge will be brought, and evaluate aggravating and mitigating factors to decide the degree.

Below, we break down how the law defines murder and manslaughter, and the circumstances under which these charges may be pressed.

If you or someone you love is facing homicide charges, it is important to seek the advice of an experienced Illinois attorney – it could mean the difference between life behind bars and a change to put things back on track.

First-Degree Murder in Illinois

In order to secure a conviction of first-degree murder, the prosecution must prove the defendant:

• Intended to kill or inflict great bodily harm upon the victim;
• Knew that the act would cause death or great bodily harm to the victim; or
• Killed the victim in the commission of a forcible felony (not second-degree murder).

First-degree murder is the most serious homicide offense in Illinois, and is punishable by life imprisonment.

Before charging the defendant with first-degree murder, the prosecution will consider any aggravating or mitigating factors. This will also be considered by the jury, which may convict the defendant of a lesser homicide offense if mitigating factors are present.

Often, courts will hold a separate sentencing hearing after conviction to determine the appropriate penalties based on the circumstances of the crime.

Second-Degree Murder in Illinois

Murder in the second-degree may be proven the same way as first-degree, and legally, second-degree murder is defined similarly. The difference, again, is intent. Prosecution may elect to press this charge instead when either mitigating factor is present:

• The defendant was under a sudden and intense passion due to serious provocation either by the victim or another person whom the defendant attempted to kill, but negligently killed the victim instead; or
• The defendant believed the killing would be lawfully justifiable, but the belief was unreasonable.

The defendant will be responsible for illustrating these mitigating circumstances at trial. If defense can show that the victim’s conduct provoked or incited behavior that would cause a reasonable person to become impassioned, the murder may be classified as second-degree.

Voluntary Manslaughter in Illinois

Manslaughter is the unintentional killing of an individual without lawful justification, and can be considered voluntary or involuntary. Where most states recognize multiple acts that constitute voluntary manslaughter, Illinois only recognizes one – the manslaughter of an unborn child.

Voluntary manslaughter occurs when:

• The defendant acts under a “sudden and intense passion resulting from serious provocation by another whom the offender endeavors to kill, but negligently or accidentally causes the death of the unborn child;” or
• The defendant intentionally or knowingly kills an unborn child, and at the time of the killing believes that the circumstances justify the killing under justifiable use of force, but this belief is unreasonable.

Any other situation will be charged as murder or involuntary manslaughter.

Involuntary Manslaughter in Illinois

Involuntary manslaughter applies to any accidental death resulting from the reckless actions of the defendant. Recklessness is the key component here – if the loss of life is negligent, this would be a civil matter in a wrongful death lawsuit.

Under Illinois law, involuntary manslaughter is defined as the following:

• The defendant unintentionally killed the victim without lawful justification
• The acts, whether lawful or unlawful, are likely to cause death or great bodily harm to the victim

With a little perspective, it is easy to see the line between manslaughter and murder is often surprisingly thin. In every case, the most important determinants are the defendant’s intent and relationship to the victim.

If the evidence point towards an intentional and premeditated offense, the crime will likely be charged as murder.

About the Author: Andrew M. Weisberg is a former felony prosecutor who now serves as a defense attorney in the greater Chicago area. He has extensive experience in handling all types of criminal cases, from sex offenses and domestic violence to retail theft-related crimes, murder, and drug crimes.