MO Rev Stat § 565.034 (2021)
2021 Missouri Revised Statutes|Title XXXVIII - Crimes and Punishment; Peace Officers and Public Defenders|Chapter 565 - Offenses Against the Person|Section 565.034 - Person under eighteen, written notice filed to seek life without parole, procedure — withdrawal — trial procedure — required findings.

Effective - 13 Jul 2016   565.034. Person under eighteen, written notice filed to seek life without parole, procedure — withdrawal — trial procedure — required findings. — 1. If the state intends to seek a sentence of life without eligibility for probation or parole for a person charged with murder in the first degree who was under the age of eighteen at the time of the commission of the offense, the state must file with the court and serve upon the person a written notice of intent to seek life without eligibility for probation or parole. This notice shall be provided within one hundred twenty days of the person's arraignment upon an indictment or information charging the person with murder in the first degree. For good cause shown, the court may extend the period for service and filing of the notice. Any notice of intent to seek life without eligibility for probation or parole shall include a listing of the statutory aggravating circumstances, as provided by subsection 6 of this section, upon which the state will rely in seeking that sentence.  2. Notwithstanding any other provisions of law, where the state files a notice of intent to seek life without eligibility for probation or parole pursuant to this section, the defendant shall be entitled to an additional sixty days for the purpose of filing new motions or supplementing pending motions.  3. A notice of intent to seek life without eligibility for probation or parole pursuant to this section may be withdrawn at any time by a written notice of withdrawal filed with the court and served upon the defendant. Once withdrawn, the notice of intent to seek life without eligibility for probation or parole shall not be refiled.  4. After the state has filed a proper notice of intent to seek life without eligibility for probation or parole pursuant to this section, the trial shall proceed in two stages before the same trier. At the first stage the trier shall decide only whether the person is guilty or not guilty of any submitted offense. The issue of punishment shall not be submitted to the trier at the first stage.  5. If the trier at the first stage of the trial finds the person guilty of murder in the first degree, a second stage of the trial shall proceed at which the only issue shall be the punishment to be assessed and declared.  6. A person found guilty of murder in the first degree who was under the age of eighteen at the time of the commission of the offense is eligible for a sentence of life without eligibility for probation or parole only if a unanimous jury, or a judge in a jury-waived sentencing, finds beyond a reasonable doubt that:  (1) The victim received physical injuries personally inflicted by the defendant and the physical injuries inflicted by the defendant caused the death of the victim; and  (2) The defendant was found guilty of first degree murder and one of the following aggravating factors was present:  (a) The defendant has a previous conviction for first degree murder, assault in the first degree, rape in the first degree, or sodomy in the first degree;  (b) The murder was committed during the perpetration of any other first degree murder, assault in the first degree, rape in the first degree, or sodomy in the first degree;  (c) The murder was committed as part of an agreement with a third party that the defendant was to receive money or any other thing of monetary value in exchange for the commission of the offense;  (d) The defendant inflicted severe pain on the victim for the pleasure of the defendant or for the purpose of inflicting torture;  (e) The defendant killed the victim after he or she was bound or otherwise rendered helpless by the defendant or another person;  (f) The defendant, while killing the victim or immediately thereafter, purposely mutilated or grossly disfigured the body of the victim by an act or acts beyond that necessary to cause his or her death;  (g) The defendant, while killing the victim or immediately thereafter, had sexual intercourse with the victim or sexually violated him or her;  (h) The defendant killed the victim for the purposes of causing suffering to a third person; or  (i) The first degree murder was committed against a current or former: judicial officer, prosecuting attorney or assistant prosecuting attorney, law enforcement officer, firefighter, state or local corrections officer; or against a witness or potential witness to a past or pending investigation or prosecution, during or because of the exercise of their official duty or status as a witness. ­­-------- (L. 2016 S.B. 590)  Effective 7-13-16