Third Degree Murder Overview

A court of law may find someone guilty of third-degree murder if they intentionally caused someone else's death while committing a dangerous act. This is different from first-degree and second-degree murder charges, which generally require intent. Some criminal statutes refer to intent as "malice aforethought."

Only three states have third-degree murder laws: Minnesota, Florida, and Pennsylvania. Each of these states has a different definition of third-degree murder, as explained in the chart below.

Third-Degree Murder in Florida, Minnesota, and Pennsylvania

Note that states have sentencing guidelines, and some have mandatory minimum sentences. The guidelines may affect one's prison sentence length. 

For example, Minnesota's sentencing guidelines suggest 12.5 years imprisonment for a first-offense third-degree murder (depraved mind). 

In Florida, third-degree murder carries a minimum sentence of 10 1/3 years with no prior record or aggravating factors. For more information, contact a criminal defense attorney near you.

What Is the Difference Between First-, Second-, and Third-Degree Murder?

In general, states require premeditation for first-degree murder, such as the defendant having planned the act. Many states also consider causing a death during a felony as first-degree murder. This is called felony murder. Other states consider a felony murder as second-degree murder.

Second-degree murder charges occur when the defendant intended to commit murder but did not plan it in advance. Some states consider it second-degree murder if the defendant intended only to cause serious bodily harm but knew or should have known that death could result from the act.

Not all states use the terms first-, second-, and third-degree murder in their criminal codes. The exact definitions of crimes vary by jurisdiction. As noted above, only three states have third-degree murder laws. Most states, though, have different levels of murder charges and impose lesser sentences for lesser crimes.

What Is the Difference Between Third-Degree Murder and Manslaughter?

Manslaughter charges, which are less serious than murder charges, arise when the defendant:

• Had no intention to kill
• Did not plan the killing beforehand
• Acted recklessly or negligently to the point that they could have avoided the killing by acting like a reasonable person

Some states split manslaughter charges into voluntary and involuntary. Others break them down into different degrees, just like with murder.

The difference between third-degree murder and manslaughter often depends on the defendant's state of mind at the time of the killing. 

In Minnesota, for example, a court may convict someone of manslaughter in the second degree if the person knew they were unreasonably risking someone else's life and took that chance. This is different from third-degree murder, where the person must act with a depraved mind and malice, which is a wanton disregard for human life.

First-degree manslaughter — also called heat-of-passion, crime of passion, or voluntary manslaughter — occurs when someone intentionally kills another person in the heat of the moment. The moment must have strongly provoked them, and they did not have time to cool off. Unlike third-degree murder, there is intent to kill. It is assumed, however, that a reasonable person would have lost control of their emotions if they'd been provoked in a similar manner.

Involuntary manslaughter, on the other hand, is the least serious of the charges. Typically, involuntary manslaughter applies when the killing is unintentional and possibly accidental. For example, a drunk driver who caused a person's death may face involuntary manslaughter charges.

Defenses Against a Third-Degree Murder Charge

Defenses to a third-degree murder charge might include the following:

• Innocence: "It wasn't me."
• Insanity: "A mental impairment prevented me from understanding what I was doing."
• Self-defense: "I was protecting myself from immediate and serious harm."
• Defense of others: "I was protecting others from serious harm."
• Exercise of duty: "I am a public officer who killed without unlawful intent, recklessness, or negligence."

Your state may also allow specific defenses to murder charges. Some states, including Florida, have a Stand Your Ground law. The law allows people to use deadly force if they reasonably believe they or someone else is in imminent danger of deadly harm. It also applies when someone reasonably believes using force is necessary to prevent another person from committing a felony. In general, these laws remove the duty to retreat.

Other states also have castle doctrine laws. These laws allow people to use deadly force in specific locations, such as one's home or property. Castle Doctrine laws also remove the duty to retreat. 

For example, suppose a person commits a home invasion in a state with castle doctrine laws and the homeowner kills the home invader. The homeowner may rely on the castle doctrine law and claim they committed a justifiable homicide.

Consider reading FindLaw's article on criminal defenses for more information.

Questions? Contact an Attorney

If the government has charged you with third-degree murder, consider hiring an experienced criminal defense lawyer. An attorney can determine what defenses you can use. They can also provide helpful legal advice on a range of topics, such as:

• Defense strategies against murder/manslaughter charges stemming from a DUI/DWI
• Whether a police officer or other law enforcement agent violated your constitutional rights
• How your state classifies different types of murder and other violent crimes, and how it may affect your criminal trial and sentencing
• General information about criminal law, murder cases, and other serious crimes

Contact a criminal defense attorney today if you or a loved one have a criminal law issue.