State of Iowa v. Sebastin Reece O'Brien

IN THE COURT OF APPEALS OF IOWA
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No. 25-0553
Filed April 29, 2026
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State of Iowa,
Plaintiff–Appellee,
v.
Sebastin Reece O’Brien,
Defendant–Appellant.
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Appeal from the Iowa District Court for Harrison County,
The Honorable Jeffrey L. Larson, Judge.
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AFFIRMED
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Martha J. Lucey, State Appellate Defender, and Melinda J. Nye, Assistant
Appellate Defender, attorneys for appellant.

Brenna Bird, Attorney General, and Louis S. Sloven, Assistant Attorney
General, attorneys for appellee.
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Considered without oral argument
by Tabor, C.J., and Badding and Langholz, JJ.
Opinion by Tabor, C.J.

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TABOR, Chief Judge.

Iowa’s uniform jury instructions advise district courts to rework the
standard marshaling instructions if the jury is considering an insanity
defense.1 Because the district court declined his counsel’s request to modify
the marshaling instructions to cross reference his insanity defense, Sebastin
O’Brien challenges the jury’s verdict finding him guilty of murder in the first
degree. Although the court did not follow a recommended practice for
instructing the jury, O’Brien cannot show that he suffered prejudice on this
record. Thus, we decline to grant a new trial.

I. Facts and Prior Proceedings

A passing motorcylist stopped to help when he saw a speeding pickup
miss a curve, skid into the ditch, and flip onto its top. When O’Brien climbed
out of the wreckage, the motorcylist noticed blood splatter on his face and
clothes. He assumed O’Brien was hurt in the accident. But it was not
O’Brien’s blood. The blood—and the crashed pickup—belonged to Douglas
Manley.

When the motorcylist refused to give the agitated man a ride into
Modale, the nearest town, O’Brien started walking. Another passing
motorist, also seeing that O’Brien had “blood all over himself” pulled over.
O’Brien jumped into that truck and demanded, “Get me out of here.” The

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A comment to Iowa Criminal Jury Instruction 200.9 (insanity defense) states:
“Caveat: If the insanity defense is submitted, then the marshaling instruction should be
modified accordingly.”See Iowa State Bar Ass’n, Iowa Crim. Jury Instruction 200.9 cmt.;
cf. State v. Hines, No. 09-0241, 2010 WL 446954, at *3 n.1 (Iowa Ct. App. Feb. 10, 2010)
(noting “it would have been appropriate and perhaps preferable to explicitly refer to the
submissible justification defense within the marshaling instruction” and comparing
justification to insanity defense).

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motorist acknowledged the blood on O’Brien and asked if he needed medical
help. O’Brien looked him in the eye and said: “It’s not my blood.” O’Brien
refused to leave the truck, so the driver reached for his pistol and used it to
strike O’Brien in the mouth. The pair struggled over the gun, with O’Brien
eventually giving up and walking back toward the crash site. The motorist
went home and called 911.

When Harrison County Sheriff’s deputies found O’Brien in the town
of Modale he was “agitated” and “combative.”2 As they tried to place him in
a patrol car, O’Brien called himself “a wanted murderer.” O’Brien then
started talking about “Doug,” saying that he was “bleeding out” and asking
the deputies to “please go save him.” At first, the deputies thought someone
else was in the crashed truck. But O’Brien clarified that he was talking about
Manley who lived in a house “south of town.” O’Brien called Manley “a
fucking pedophile” and admitted that he took Manley’s truck after
“beat[ing] the fuck out of him.”

Emergency personnel took O’Brien to the hospital because of possible
trauma from the rollover accident and because his mouth was bleeding from
the scuffle with the other motorist. An emergency room doctor testified that
he did not see any signs that O’Brien was suffering from a psychotic episode.

Meanwhile, the deputies learned that the crashed truck was registered
to Manley and rushed to his house. They found his body amid a bloody crime
scene. Manley had been beaten with such force that his face was
unrecognizeable. O’Brien later told his mother that he struck Manley with

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Many people who interacted with O’Brien before his arrest noticed signs of
intoxication including the smell of alcoholic beverages, slurred speech, bloodshot eyes,
and impaired balance. A sample taken at the hospital showed a blood alcohol content of
.099.

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pieces of wood and stomped on his face. O’Brien’s blows knocked out several
of Manley’s teeth, four of which he swallowed before he died, according to
the autopsy.

In a series of recorded calls from the jail, O’Brien gave varying versions
of what happened at Manley’s house. In one call, he acknowledged that he
was “probably going down hard” for what he did.

Indeed, the State charged O’Brien with murder in the first degree in
violation of Iowa Code section 707.1 and 707.2(1)(a) (2024). O’Brien told the
court that he would be relying on the defenses of insanity, diminished
responsibility, intoxication, and self-defense.

For the insanity defense, O’Brien lined up Dr. Christina Pietz as his
expert witness, and she completed an evaluation of O’Brien. She chronicled
for the jury O’Brien’s history of psychiatric treatment, including a brief
hospitalization in February 2022 when he was having auditory and visual
hallucinations. Later that same year, he was hospitalized for six months and
diagnosed with psychosis. Records also show previous diagnoses of paranoid
schizophrenia and bipolar disorder. Dr. Pietz believed that when O’Brien
killed Manley he was acting under the delusion that Manley had raped him
and sexually trafficked children. As her bottom line, she offered her opinion
that O’Brien suffered from a schizoaffective disorder, leaving “him incapable
of knowing the quality and nature of his actions” and unable to distinguish
right from wrong.

To rebut Dr. Pietz’s opinion, the State called Dr. Rosanna
Jones-Thurman, who also examined O’Brien and reviewed the evidence. In
her view, O’Brien “understood the nature and quality” of his actions and had
no condition that rendered him insane at the time of the murder. From

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conducting inventory tests, she found that O’Brien was “malingering
symptoms.” In other words, he was “exaggerating” by giving answers that
would make him “look psychotic.”

The jury rejected his insanity defense and convicted O’Brien of
murder in the first degree. He appeals.

II. Scope and Standard of Review

We review jury instruction challenges for the correction of legal error.
State v. Kraai, 969 N.W.2d 487, 490 (Iowa 2022). We consider the entire set
of instructions to decide whether they accurately conveyed the law to the
jurors. Id. While they should generally track the uniform instructions, district
courts are not bound by any model in formulating their directions to the jury.
State v. Davis, 975 N.W.2d 1, 9–10 (Iowa 2022); see also State v. Ellison, 985
N.W.2d 473, 479 (Iowa 2023). We will reverse only when the instructions
resulted in prejudice by misleading the jury or materially misstating the law.
State v. Benson, 919 N.W.2d 237, 241–42 (Iowa 2018).

III. Analysis

To avoid responsibility for the brutal murder, O’Brien pursued an
insanity defense. His lawyer told jurors in opening statements: “It was clearly
a delusional attack that took the life of Douglas Manley.” When it came time
to finalize the jury instructions, O’Brien asked to modify all the marshaling
instructions to cross reference the instructions defining legal insanity. For the
top charge, O’Brien proposed telling the jury: “If the State has proved all the
elements, the defendant is guilty of murder in the first degree. You must then
consider the defense of insanity as described in Instruction Number . . . .”
O’Brien also asked for a similar sentence to be included for all the lesser
included offenses being marshalled.

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The State resisted the request, contending that separating the
marshaling instructions from the affirmative defense instructions would
make “more sense to a jury.” The prosecutor argued that the separation
would “make it much easier for the parties to clarify for the Court whose
burden [it] is to prove each one of these elements. And since it’s their burden
to prove insanity, it’s better to separate it out.” The district court agreed with
the State and denied O’Brien’s request to alter the marshaling instructions.

On appeal, O’Brien argues that the district court erred in refusing to
include the suggested language and that we should presume prejudice. For
this argument, O’Brien cites State v. Davis, 951 N.W.2d 8, 16 (Iowa 2020).

But Davis doesn’t support his position. That case involved a claim that
counsel was ineffective for not objecting to the marshaling instruction for
first-degree murder because it did not mention the insanity defense, while
the marshaling instructions for the lesser-included offenses did. Id. at 20. Our
supreme court reasoned: “When the marshaling instructions for the other
nine offenses cross-referenced the insanity defense but not the instruction for
first-degree murder, the jurors would reasonably conclude that omission was
intentional and the defense was unavailable.” Id. at 19 n.1. By contrast, the
maxim that the “expression of one thing is the exclusion of another” is not
at play here. See Davis, 951 N.W.2d at 19 n.1; see also Vagts v. N. Nat. Gas Co.,
8 N.W.3d 501, 516 (Iowa 2024) (translating the Latin phrase “expressio unius
est exclusio alterius”). None of the marshaling instructions for O’Brien’s
trial cross-referenced his insanity defense. So the question is whether the
district court erred in rejecting O’Brien’s request to modify all the
marshaling instructions.

We decline to find that the district court erred by not following the
comment from the uniform instructions. To be clear, we value the work of

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the Iowa State Bar Association members on that advisory committee. See
State v. Robinson, 859 N.W.2d 464, 490 (Iowa 2015) (Wiggins, J., specially
concurring) (recognizing that “the ISBA committee appointed to formulate
these instructions is industrious and does its best to get the law right”). And
it’s true that “we generally prefer the uniform instructions be followed by
trial courts.” State v. Holtz, 548 N.W.2d 162, 164 (Iowa Ct. App. 1996). But
despite our broad endorsement of the uniform instructions, courts cannot
“delegate the formulation of the law to the instruction committee.” Robinson,
859 N.W.2d at 490. And beyond that, the Davis court did not endorse the
concept of modifying the marshaling instructions to cross-reference the
insanity defense in every case. In our review of O’Brien’s prosecution, we find
that the instructions accurately stated the law and were not misleading. See
Ellison, 985 N.W.2d at 479 (“[T]he court must merely give instructions that
fairly state the law as applied to the facts of the case.” (citation omitted)).

And even if it would have been preferable to cross-reference the
insanity defense in the marshaling instructions, this record leaves no question
that the jurors had ample notice that the defense was an option. True, in
closing argument, the prosecutor said: “The State submits to you you will go
no farther than the first count, the first charge of murder in the first degree.
You will be firmly convinced and are firmly convinced after hearing all the
evidence.” But that was not the end of the story.

In its closing, the defense highlighted the three jury instructions—
numbered 45, 46, and 47—discussing O’Brien’s insanity defense. Defense
counsel quoted Instruction 46: “Insanity need not exist for any specific
length of time before or after the commission of the offense.” Counsel also
reminded the jury of his client’s “long history of delusions, hallucinations

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both auditory and visual, schizophrenia, schizoaffective disorder, [and]
bipolar.” And counsel pointed to the testimony of the defense expert:
Dr. Pietz testified to you within a reasonable degree of
psychological certainty that on April 21st, 2024, Sebastin O’Brien suffered
from a diseased or deranged condition of the mind as to render him
incapable of knowing the quality and nature of his actions and was
incapable of distinguishing between right and wrong. That was her opinion
as a doctor and as a psychologist.

She also testified within a reasonable degree of psychological
certainty that Mr. O’Brien was actively psychotic on April 21st, 2024, and
was incapable of knowing the difference between right and wrong as he was
assaulting Douglas Manley which ultimately resulted in Douglas Manley’s
death.

Defense counsel then tried to discredit the testimony of the State’s expert,
Dr. Jones-Thurman. Counsel capped that part of his argument by saying that
Dr. Pietz’s opinion “conforms nearly identically with Jury Instructions 45,
46, and 47.”

The jurors also heard the State discuss that defense in its rebuttal
closing argument: “Let’s talk about legal insanity, because I think it’s
important that we have a clear understanding of what it is and what it is not
and whose burden it is in this case.” The prosecutor explained that it was
O’Brien’s burden to prove that he was insane. And added: “I submit to you
that based on this evidence that’s been presented in this courtroom, we not
only proved each and every element beyond a reasonable doubt, but we
disproved beyond a reasonable doubt that he was insane at the time.”

Given the robust back-and-forth discussion on the insanity defense in
closing arguments, no juror could reasonably conclude that the insanity
defense was unavailable to O’Brien. This case is unlike Davis. Because the
instructions were accurate statements of the law and did not distort the

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options before the jury, they were not prejudicial to O’Brien. Thus, we
decline to order a new trial.

AFFIRMED.

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