Idaho First-Degree Murder

Under Idaho law, homicide is the unlawful killing of another human being. Intentional homicide is murder, the most serious crime someone can commit in Idaho. Idaho’s criminal code recognizes two degrees of murder, depending on the nature of the act.

Both first- and second-degree murder receive punishments of up to life imprisonment. First-degree murder has specific requirements for what qualifies for the crime. The prosecutor must request the death penalty to get the maximum sentence.

Idaho is one of 27 states with the death penalty for aggravated first-degree murder. In 2026, Idaho is slated to make a firing squad as its primary method of execution.

Idaho First-Degree Murder Laws

Idaho codes define murder as the unlawful killing of a human being with malice aforethought. Malice may be:

• Express when the defendant expresses an intention to kill another person
• Implied when the defendant kills without adequate provocation or displays “an abandoned and malignant heart”

First-Degree Murder Charges

First-degree murder exists when the defendant:

• Uses poison, lies in wait, or shows any deliberation or premeditation in executing the act
• Uses torture intended to cause suffering, for extortion, for revenge, or for sadistic personal satisfaction, resulting in the victim’s death
• Causes the murder of any peace officer, prosecuting attorney or other law enforcement officer or agent of the court in the course of their official duties
• Attempts to or completes any act of sexual abuse or aggravated battery against a child under 12 years of age resulting in the death of the child
• Is an inmate in an Idaho State Correctional Center facility and commits murder against any other inmate, corrections officer, staff member, or visitor
• Commits any other enumerated felony resulting in death (“felony murder rule”)

All other unlawful homicides are second-degree murders.

Idaho’s felony murder rule means that any participant in a crime may face first-degree murder, even if the participant did not commit the murder or intend that a death result from the crime.

Idaho First-Degree Murder Penalties

In the state of Idaho, all defendants guilty of murder of the first degree must receive the death penalty or life imprisonment. The prosecuting attorney must file a notice of intent they will seek the death penalty before trial. Without such notification, the court must instruct the jury that the death penalty is not a sentencing option.

If the prosecuting attorney does not seek the death penalty or if the court determines the sentence is unjust, the defendant must receive a life sentence with a minimum of 10 years before eligibility for parole or early release.

Possible Defenses Against First-Degree Murder Charges in Idaho

Idaho has an affirmative “stand your ground” law. If the defendant claims a homicide was self-defense, the burden shifts to the prosecution to show that the use of force was unreasonable and unjustified.

Idaho law presumes that individuals have the right to defend themselves if they are in their own homes or any location where they have a lawful right to be. The law presumes that any individual who unlawfully attempts to enter a habitation or location by force or stealth intends to commit a felony therein.

Excusable homicide occurs when it happens by accident, performing a lawful act by lawful means, with all due caution. If the defendant acts carelessly or negligently, they may face manslaughter charges.

Get Legal Advice From an Idaho Criminal Defense Attorney

First-degree murder charges are among the most serious charges anyone can face. If you or a loved one face any degree of murder charges, speak with an Idaho criminal defense lawyer. An attorney skilled in criminal law will examine your case, explain your options, and stand with you in all legal proceedings.