Idaho Title 18 is the state’s criminal code, and it does two main things: it sorts every offense into felonies, misdemeanors, or infractions, and it sets the prison time, jail time, and fines a judge can impose for each crime. This guide walks through how Idaho Title 18 crimes and penalties are organized, from how an offense gets classified to the specific sentencing ranges for homicide, assault, battery, robbery, burglary, and theft.
How Idaho Sorts Crimes
Every criminal offense in Idaho falls into one of three tiers. A felony is any crime punishable by death or by time in the state prison. A misdemeanor is any other crime that does not reach the felony threshold. An infraction is not a crime at all in the technical sense. It is a civil public offense, capped at a $300 fine, with no jail time attached.1Idaho State Legislature. Idaho Code 18-111 – Felony, Misdemeanor and Infraction Defined
One important wrinkle sits inside that definition. When a crime technically qualifies for state prison, but the judge instead hands down a county jail sentence or a fine alone, the offense is treated as a misdemeanor from that point forward.1Idaho State Legislature. Idaho Code 18-111 – Felony, Misdemeanor and Infraction Defined The sentence imposed, not the sentence available, controls the classification.
Homicide: Murder and Manslaughter
Idaho defines murder as the unlawful killing of a human being with malice aforethought, or through the intentional use of torture resulting in death. The statute includes a human embryo or fetus within that definition.2Idaho State Legislature. Idaho Code 18-4001 – Murder Defined
First- and Second-Degree Murder
First-degree murder covers killings that are willful, deliberate, and premeditated. It also includes murders carried out by poison, lying in wait, or torture, along with killings committed during arson, robbery, burglary, kidnapping, or rape. Murders of law enforcement officers, firefighters, judges, or prosecutors acting in an official capacity are automatically first degree, as are killings committed by inmates or people escaping from prison.3Idaho State Legislature. Idaho Code 18-4003 – Degrees of Murder Any murder that does not fit one of those categories is second degree.
First-degree murder is punishable by death or life in prison. Second-degree murder carries up to life in prison but is not eligible for the death penalty.
Manslaughter
Manslaughter is an unlawful killing without malice. Voluntary manslaughter happens during a sudden quarrel or in the heat of passion, and it carries up to 15 years in state prison and a fine of up to $15,000. Involuntary manslaughter covers deaths caused during an unlawful act that is not one of the felonies that triggers a murder charge, or deaths resulting from a lawful act performed in a reckless or careless way, including the reckless handling of firearms. The maximum penalty is 10 years in prison and a $10,000 fine.4Idaho State Legislature. Idaho Code 18-4007 – Punishment for Manslaughter
The dividing line between voluntary manslaughter and second-degree murder often turns on whether the defendant acted in the heat of the moment or with actual malice.5Idaho State Legislature. Idaho Code 18-4006 – Manslaughter Defined
Assault and Battery
Idaho treats assault and battery as two separate offenses. Assault requires no physical contact. Battery does.
Assault Penalties
An assault is either an unlawful attempt to physically injure someone (with the apparent ability to do so) or an intentional threat of violence that creates a real fear of imminent harm.6Idaho State Legislature. Idaho Code 18-901 – Assault Defined Simple assault is a misdemeanor carrying up to three months in county jail and a fine of up to $1,000.7Idaho State Legislature. Idaho Code 18-902 – Assault Punishment
Aggravated assault is a felony. It applies when the assault involves a deadly weapon, a means likely to produce great bodily harm, or a caustic chemical. An unloaded or defective firearm still counts as a deadly weapon under the statute.8Idaho State Legislature. Idaho Code 18-905 – Aggravated Assault Defined The sentence can reach five years in state prison and a $5,000 fine.9Idaho State Legislature. Idaho Code 18-906 – Aggravated Assault Punishment
Battery Penalties
Battery is the willful use of force against another person, unlawful touching or striking against someone’s will, or intentionally causing bodily harm.10Idaho State Legislature. Idaho Code 18-903 – Battery Defined Simple battery is a misdemeanor with a maximum of six months in county jail and a $1,000 fine. If the victim is pregnant and the defendant knew it, the ceiling doubles to one year in jail.11Idaho State Legislature. Idaho Code 18-904 – Battery Punishment
Aggravated battery is a felony. It covers batteries that cause great bodily harm, permanent disability, or permanent disfigurement, as well as batteries involving a deadly weapon, poison, or a caustic chemical. A separate provision covers battery on a pregnant woman that causes serious harm to the embryo or fetus.12Idaho State Legislature. Idaho Code 18-907 – Aggravated Battery Defined The maximum sentence is 15 years in state prison.13Idaho State Legislature. Idaho Code 18-908 – Aggravated Battery Punishment
Robbery, Burglary, and Theft
These three crimes get mixed up constantly. Idaho treats them as distinct offenses with different elements and very different penalties.
Robbery
Robbery is the taking of personal property from another person, or from their immediate presence, through force or fear.14Idaho State Legislature. Idaho Code 18-6501 – Robbery Defined Direct confrontation with the victim is what separates it from theft. Robbery is always a felony. Weapon use or injury inflicted during the robbery pushes sentencing higher.
Burglary
Burglary is entering any building, vehicle, tent, railroad car, or similar structure with the intent to commit theft or any felony inside.15Idaho State Legislature. Idaho Code 18-1401 – Burglary Defined Nothing has to be stolen and no other crime has to be completed. The intent at the moment of entry is the offense. Someone invited inside who then decides to steal has committed theft, not burglary, because there was no unauthorized entry with prior criminal intent. Burglary carries one to ten years in state prison.16Idaho State Legislature. Idaho Code 18-1403 – Burglary Punishment A burglar who confronts someone inside and uses force or threats to take property can be charged with both burglary and robbery.
Theft
Idaho consolidated the older property crimes (larceny, embezzlement, fraud) into one theft statute. A person commits theft by wrongfully taking, obtaining, or withholding another person’s property with the intent to deprive the owner of it.17Idaho State Legislature. Idaho Code 18-2403 – Theft
The grading depends on value and the type of property. Grand theft covers property worth more than $1,000 and certain items regardless of value, including firearms and livestock. When the value exceeds $1,000, the maximum sentence is one to twenty years in state prison and a fine of up to $10,000. Grand theft involving listed property categories such as firearms and livestock carries one to fourteen years and a fine of up to $5,000. Petit theft is the misdemeanor tier, capped at one year in county jail and a $1,000 fine.18Idaho State Legislature. Idaho Code 18-2408 – Punishment for Theft
When Self-Defense Is Justified
Idaho provides broad protection for people who use force to defend themselves, others, or their property. A homicide is justified when it happens while resisting an attempt to murder, commit a felony, or inflict great bodily harm on any person.19Idaho State Legislature. Idaho Code 18-4009 – Justifiable Homicide by Any Person
Idaho’s castle doctrine is particularly strong. You can use force, including deadly force, to defend your home, business, occupied vehicle, or other property against someone who is clearly attempting to commit a felony or who is forcing entry to harm someone inside. The law adds a presumption: anyone who enters your home, workplace, or occupied vehicle unlawfully and by force or stealth is presumed to be doing so with the intent to commit a felony.19Idaho State Legislature. Idaho Code 18-4009 – Justifiable Homicide by Any Person
The protection also extends to defending family members and others when there is a reasonable belief that a felony or great bodily injury is about to occur and the danger is imminent. One limit matters: a person who was the initial aggressor or who was engaged in mutual combat must have made a genuine, good-faith effort to disengage before using deadly force.19Idaho State Legislature. Idaho Code 18-4009 – Justifiable Homicide by Any Person
Default Penalties When a Statute Is Silent
Most Title 18 offenses have their own penalty written into the statute. When a crime is labeled a felony and no specific punishment is listed, the default is up to five years in state prison and a fine of up to $50,000, or both.20Idaho State Legislature. Idaho Code 18-112 – Punishment for Felony The misdemeanor default is up to six months in county jail and a fine of up to $1,000, or both.21Idaho State Legislature. Idaho Code 18-113 – Punishment for Misdemeanor These ceilings only apply when the individual offense statute says nothing about sentencing. The specific penalties listed above for the major Title 18 crimes override these defaults.
How Long Prosecutors Have to File Charges
Idaho generally gives prosecutors five years to file charges on a felony. After that, the state loses the ability to bring the case in most situations.22Idaho State Legislature. Idaho Code 19-402 – Commencement of Prosecution Murder has no statute of limitations and can be charged decades after the killing. Certain sex crimes against minors have their own extended filing windows. These deadlines live in Title 19 rather than Title 18, but they control when any Title 18 offense can be prosecuted.