Filed 9/29/21 CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

SIXTH APPELLATE DISTRICT

THE PEOPLE, Plaintiff and Respondent,

v.
BYRON SILIM SUMAGANG , Defendant and Appellant. H044023 (Monterey County Super. Ct. No. SS143024 )

This case concerns the admissibility of statements the defendant made as the result
of a two

- part interrogation

. The detective who questioned the defendant withh e ld
Miranda warnings, elicited a complete confession, and then re

- interrogated him about the
same facts after warning him under Miranda

. In both the prewarning and postwarning parts of the interrogation, d efendant Byron S i lim Sumagang confessed that he killed his girlfriend as part of a botched d ouble

- suicide attempt. After the postwarning statements

w ere admitted at trial, the jury found him guilty of first degree murder. The trial court imposed a term of 25 years to life in state prison. Sumagang contends the trial court erred by denying his motion to exclude the
confession under Missouri v. Seibert (2004) 542 U.S. 600, 608 ( Seibert ). We hold that the trial court did so err, and we find Sumagang was prejudiced by the admission of the
confession at trial. We will reverse the judgment of convi ction. 1

1 Sumagang raises other claims as set forth in section II.B

. , but we do not reach th o se claims.2 I. F ACTUAL AND P ROCEDURAL B ACKGROUND The p olice found Sumagang asleep in the back of a car in a remote rural area

. Carole Sangco’s deceased body was lying on top of him. The police took Sumagang into custody and a detective subsequently inte rviewed him in two stages

— first without warning him under Miranda , and then again after warning him. In both parts of the interview, he admitted choking Sangco until she stopped breath ing or moving. He
claimed she had asked him to kill her, and he said he had intended to kill himself as well. Sangco , who was 20 years old, suffered from depression and had previously expressed suicidal thoughts

. Toxicology tests showed she had a “poten tially toxic” level of drugs in her body at the time of death. The prosecution charged Sumagang with the willful, deliberate, and premeditated murder of Sangco. (Pen. Code, § 187, subd. (a).) The jury found him guilty as charged. The trial court sentenced him to a term of 25 years to life in state prison.
The jury heard the following evidence:
A. Discovery of the Car On the morning of November 30, 2014, the police responded to a hang

- up 911 call
from a remote rural area in Montere y County. A sheriff’s deputy found a car with the hood up, a large crack in the front windshield, and the cap to the gas tank hanging open. Sumagang and Sangco were in the back seat and appeared to be asleep. Sang c o was lying on top of Sumagang with her face “up in the window.” She had a cut and some dried blood above her right eye. When the deputy knocked on the window, Sumagang woke up but Sangco did not. Sumagang got out of the car, whereupon the deputy handcuffed him, searched him and put him in her patrol car. Sumagang, who was upset and crying, told the deputy that Sangco was his girlfriend, and he said they had both “taken a bunch of Klonopin and drank as much tequila as the y could” the previous evening. The deputy testified that Sumagang tol d her he was “ not supposed to wake up ,” and he was “supposed to be with3

the female.” Later, when the deputy escorted Sumagang to an ambulance, he stated he

“ did this to her, ” referring to Sangco. Another officer testified that when he asked Sumagang how Sangco received injuries to her face, he replied, “I did that to her.” Investigators found numerous items in and around the car. A bottle of tequila was found on the ground in front of the car, a nd a package of cigarettes had been stuffed into the engine. There was a knife wedged behind the backseat of the car , and another knife was found on the ground (possibly after the deputy removed it from the car). A partially burned piece of paper had bee n stuffed into the neck of the gas tank. A shoeprint was
found near the crack in the front windshield.
B. Post warning Confession Police interrogated Sumagang about two days after taking him into custody. The post warning portion of the interrogation was recorded on video , which the prosecution
showed to the jury. Sumagang said he and Sangco had been together for five years. Sangco had “depression problems” and had “always been a cutter.” She “just hated breathing ” and “didn’t wanna be a part of this shitty ass world.” On the night of her death, they drove to the remote location while drinking a bottle of tequila

. Sangco was using a small pocketknife to cut her wrists. Sumagang also tried to use a knife to cut hi s own wrists
and neck. At some point after they parked, Sumagang tried to set the car on fir e by putting a pair of boxers soaked in tequila into the engine oil

. He hit his head on the windshield during a tantrum, and probably broke the windshield by kic king it. During a break in the interview , while Sumagang was alone, he began crying and said, “ I’m so sorry, Carole. It was supposed to be us together

. [.

. .] I’m so sorry. [.

. .] I just wanna die

. ” When the officer asked how Sangco got the inju ries to her head, Sumagang said he “[p]robably head

- butted her” at the same time he had his “hands on” her. Sumagang said4

he thought he hit her twice. When the officer asked him to explain what he did, Sumagang replied, “I didn’t want

. . . even want to. Then she just kept on telling me to. Then I said, ‘Fine, I’ll

. . .’ I just wanted to die together. I didn’t wanna hurt her. But then she wanted that. And then so I gave it to her.” According to Sumagang, Sangco told him, “ ‘ P lease, give it to m e. Don ’ t stop. ’ ” At some point, she closed her eyes, her arms went limp, and she “just stopped moving.” He tried to pick her up, but she was already dead, so he just put her in his lap. Sumagang added, “But then

. . . I forgot to kill myself, too, bec ause

. . . . [.

. .] I forgot to kill myself. I was supposed to

. . . .”
C. Autopsy Results and Cause of Death Dr. Venus Azar, a forensic pathologist, autopsied Sangco’s body. Outside the presence of the jury, Dr. Azar testified that prior to forming h e r conclusions about the cause of death, s he was “informed thoroughly” by the coroner’s detectives about Sumagang’s statements, and s he watched part of a video of the detective’s interview. Specifically, Dr. Azar was told Sumagang head

- butted Sangco, used his hands to squeeze her neck, and put his hands over her nose and mouth until she stopped breathing. When Dr. Azar was asked how she used this information in forming her conclusion, she
testified that she used the information to see if it fit with the injuries she had observed in her examination, but she a lso testified that the information did not change her conclusion or any of her physical findings. In the presence of the jury, Dr. Azar testified that s he observed multiple external injuries to Sangc o’s body , including a bruise on the side of her head above her left ear; petechiae (dot

- like hemorrhages) on her face, in her eyes, above her upper lip, and on her left ear; a laceration on her right eyebrow; a bruise with a slight abrasion on her lower li p; about seven abrasions or scratches to her neck and under her chin ; some minor abrasions on her wrists and legs; and a half

- inch bruise on her tongue

. T he external injuries were
the result of blunt force trauma. Sangco also had a postmortem tooth impre ssion on her lower lip, but it could not have been caused by the medics.5

Dr. Azar testified that she saw “quite a bit of dot

- like hemorrhages, we call petechiae, on the face, and in [Sangco’s] eyes, around her eyes, and on her eyes and in
her mouth and on her left ear , ” as well as above her upper lip. Dr. Azar explained that “petechiae are dot

- punctate hemorrhages. [I]t’s a disease process that people can have if they’re dying from multiple things, such as severe burns, or severe infections/or sepsis. They can develop a process from damage to their blood vessels that is called diffused intervascular coagulation[]. ” She then testified that “we all see petechiae in strangulation” and “in other cases such as blunt

- chest trauma or compressions , severe

com pression of the chest, because [] what the strangulation and the hanging or severe
blunt

- chest trauma have in common is they block egress or outflow of blood draining
from the neck , and either by pressure on the neck from hanging or strangulation, or from severe pressure to the chest, in severe blunt trauma or compression of the chest, and that raises the pressure in the head and the neck. [¶] Severe vomiting, [] coughing severely can cause the same kind of pressure. Some types of heart failure can cause pressure to build up in the lungs because the veins can’t drain and they get stagnated and they build up the pressure and then [] blood vessels get injured and they start to die an d they start to rupture and they cause these little dot

- like hemorrhages. ” Dr. Azar testified that Sango had i n juries that “appeared to have been[] caused by someone else. She has multiple planes of injury to the head, to the left front of her scalp,
bi g bruise. The right eyebrow, the lower eyelid. So I want to know from the investigator what happened. [¶] Was this woman in a car accident? Did she fall? You know, tumble, not just on one surface, but to explain these different areas. Also the neck injuries and the tongue bruise. Does she have a reason to have bit her tongue? Is she an epileptic? [ I ] need to know what happened to her. She can’t t ell me. I need someone
else to tell me. And she had these scratches to her neck. Those are worrisom e for an
assault. ”6

Based on the petechiae , the imprint of Sangco’s tooth on her lip, and the bruise on her rib, together with the information s he had been told, Dr. Azar concluded that the cause of death was asphyxiation due to smothering with manual st rangulation. Sh e determined that t he manner of death was homicide. She testified that petechiae can be caused by severe chest trauma if it is strong enough to increase chest pressure enough to prevent blood from flowing back into the chest, but she did n ot believe the petechiae were caused by the medics’ resuscitation efforts. Dr. Azar also ordered toxicology tests of Sang c o’s blood. Sh e testified that Sangco tested positive for methamphetamine and cocaine , but these results did not change Dr. Azar’s o pinion about the cause or manner or death. The results indicated a potentially toxic level of methamphetamine. Dr. Azar opined that it is possible the drug overdosage may have hastened Sangco’s death while being asphyxiated , but Dr. Azar did not believe the drugs killed Sangco

. Dr. Azar testified that pressure on the neck can cause petechial hemorrhaging without causing death. On cross

- examination, she agreed that if someone tries to strangle a person, and the person tries to fight and breathe, raising the person’s chest pressure, that can cause petechiae without causing death. Dr. John Hain, a retired forensic pathologist, testified for the prosecution. He reviewed the police reports, medical records, and the autopsy report , among other
records

. He opined that the cause of death was asphyxiation due to suffocation, strangulation, or both. From the autopsy photographs, he observed numerous petechiae under Sangco’s eyelids and in the whites of her eyes

. Such petechiae can result fr om strangulation as the build

- up of blood in the head and the increase in blood pressure causes blood vessels to rupture

. Dr. Hain based his opinion on the amount of petechiae , the tongue injury, and other injuries. Dr. Hain testified that in strangulat ion cases, “because of pressure on the neck, there’s often forcing

—

there’s a forcing of the tongue, tip of the tongue, between the teeth7

and with the upper

— usually upward pressure on the jaw during strangulation, there are often bite mark hemorrhages or br uises within the tongue itself. And in this case the decedent exhibited all those findings. And it’s a very characteristic constellation of findings that’s seen that makes that conclusion fairly straightforward in this case.” He agreed that a person can have petechiae even if they do not die from choking. He testified that chest compressions from resuscitation rarely cause as many petechiae as he
observe d in this case.
Dr. Hain did not detect any internal neck injuries , and he did not see any pressure
marks or abrasions on Sangco’s neck that would show she had been manually strangled

. However, h e had seen other cases of strangulation with no external markings on the neck. Dr. Joseph Cohen testified for the defense a s an expert in forensic pathology. He reviewed paramedic reports, emergency room reports, police reports, Sumagang’s police interview, Dr. Azar’s autopsy report, autopsy photos, and Sangco’s toxicology report. Dr. Cohen disputed Dr. Azar’s description of the “numerous petechial hemorrhages ” on Sangco’s face

. Based on the autopsy photographs, Dr. Cohen testified that there were “maybe scattered petechial hemorrhages” and none were large. He testified that “the photographs do not really depict the extent of the petechial hemorrhages in comparison to Dr. Azar’s description of those because she describes them as being numerous on the face and the eyes and the oral cavity and so forth. ” Dr. Cohen did not see numerous petechial hemorrhages on Sangco’s face. In the photographs of her eyes, Dr. Cohen saw “ maybe scattered petechial hemorrhages. I don’t see any large ones. [¶] And on the face I see acne or folliculitis that seems to be pretty extensive. And so, you know, I’m a little hard pressed to kind of c onnect Dr. Azar’s description with what the photographs show, and it may be that the photographs just aren’t adequate or maybe for whatever reason they don ’ t depict the petechial hemorrhages

. ”
Dr. Cohen opined that the petechiae were consistent with the chest compressions that would have been applied as part of resuscitative measures or CPR by para medics

.8

He had observed many cases in which ne c k compression, strangulation, or suffocation had caused petechial hemorrhaging but did not result in death. He added that chest compressions can cause petechial hemorrhages even if a person is already dead and
cannot be revived. When asked if the efforts to resuscitate Sang c o could have caused the petechiae in Sang c o, Dr. Cohen responded, “[S]he did have some, you know, initial resuscitative efforts imposed on her by paramedics. She made it to the emergency room. They had defibrillator pads on. And they did a lot. They put in a breathing tube,
intravenous lines. So through manipulation of the body, and even through intubation, putting the tube in, they bring the head back. So I don’t want to put any inappropriate emphasis on that, but it’s possible.”
Dr. Cohen t estified that head trauma did not cause or contri bute to Sangco’s death , and there were no life

- threatening or lethal blunt

- trauma injuries to her head

. The absence of any internal neck injuries , as observed in Sangco, wa s atypical in strangulations. He explained, “in this case, with the absence of any internal neck injury

— there’s no soft

- tissue injury inside the neck, front or back; there’s no fracture of the hyoid bone, the U

- shaped bone above the voice box; there’s no hemorrhages in the strap muscles of the neck, either superficial or deep; there are no fractures of the cartilages of the neck, basically no injuries; everything I described by Dr. Azar’s being entirely normal inside the neck

— that is highly atypical in cases of strangulation.”
Dr. Cohen opined that the drugs were a factor in Sangco’s d eath. It is possible that Sangco survived the neck compression, developed petechial hemorrhages, and subsequently died from drug toxicity. He concluded that the cause of death was “not entirely clear.” He disagreed with Dr. Azar’s conclusion that it was asphyxia due to smothering through strangulation. He opined that the cause of death could have been drug toxicity with neck compression as a contributing factor. He testified that it was also possible Sang c o died of a drug overdose five or 20 minutes af ter some degree of neck compression.9

D. Testimony from Sangco’s Friends Junelle Nuno was a close friend to both Sumagang and Sangco. She had seen Sumagang act violen tly toward Sang c o on two occasions. At some point prior to 2014, she was sitting in a car parked next to their car outside a 7

- Eleven when she saw Sumagang yelling at Sangco. Nuno then saw Sangco’s face hit the window, and Sangco put her arms up in front her face to shield herself. On another occasion before that, Nuno saw Sumagang and Sa ngco arguing when he elbowed her in the face, causing Sangco to
cover her face. Sumagang started crying and apologized. A rift developed between Nuno and Sangco when Sangco began using heavy drugs like methamphetamine. Sangco talked about suicide a lot , and Nuno became afraid
for her. Sangco threatened to commit suicide, but Nuno was unaware of any actual attempts. Sangco once threatened to commit suicide so that Sumagang would not leave her, and she burned a cigarette on her arm because he made her m ad. Marlen Luna was Sangco’s friend, and she also knew Sumagang. Luna and her boyfriend frequently did drugs with Sumagang and Sangco, including methamphetamine
and cocaine. Sangco told Luna that she (Sangco) had once gone to the hospital as a result of trying to kill herself. Once in 2014, Luna saw a cracked windshi eld in the car Sumagang and Sangco were in

. Sumagang and Sangco had been mad at each other
earlier. Sangco was throwing socks at Suma ga ng, and he threw a cup toward her but did
not hit her. Luna never saw Sumagang physically abuse Sangco or put his hand s on her.
E. Testimony of Sangco’s Psychiatrist Dr. Renee Hill saw Sangco in the summer of 2013 after she was admitted to the hospital on an inpatient basis for severe depression. Sang c o was “actively suicidal” and
said she was “ having wishes to die and was comfortable with just dying if that happened to her.” Dr. Hill wrote in a report that Sangc o was enticed with “[a]llowing herself to be
killed , ” which Dr. Hill described as “passive suicidal thinking.” Sangco also thought about using a gun to shoot herself or driving her car into a heavy object , but she told Dr.10

Hill she had never attempted sui cide

. Sangco appeared more stable and hopeful after being released, but she stopped attending appointments by October 2013.
II. D ISCUSSION A. Admission of the Post warning P art of the Interview A detective interviewed Sumagang in two stages

— before administering
Miranda 2 warnings , and then again after warning him. Sumagang moved pretrial to exclude all statements he made during the entirety of the interview under Miranda and on the ground the statements were involuntary. The trial court held a hear ing at which the detective, Terry Rahiri , testified about the circumstances of the interrogation as set forth
below. The trial court excluded the pre warning portion of the interview but admitted the postwarning portion. Sumagang contends the trial court erred by denying his motion to
exclude the postwarning portion. 3 The Attorney General contends the trial court proper l y admitted it because the interview w as voluntary and the detective did not intentionally
undermine the Miranda warning s

. For the reaso ns below, we conclude the trial court erred by admitting the postwarning portion of the interview.
1. Circumstances Preceding the Inter rogation
Detective Terry Rahiri , the lead detective on the case, had been at the Monterey County Sheriff’s office for 22 years

. He testified that prior to the interrogation he had
been briefed on the case by the deputy sheriff who was at the scene, but the cause of death had not yet been determined. Detective Rahiri said he did not have a “complete idea” and “there was a b ig piece of the puzzle missing.” 4

2 Miranda v. Arizona (1966) 384 U.S. 436 ( Miranda ). 3 Sumagang also contends his trial counsel was ineffective to the extent counsel may have failed to preser ve this claim. The Attorney General concedes trial counsel preserved the issue , so we do not address the claim of ineffective assistance.

4 The record includes a police report by Detective Rahiri attached as an exhibit to an earlier motion. In the repo rt, Detective Rahiri stated he arrived at the scene of the crime and examined various pieces of evidence after other officers had taken Sumagang into custody. Another officer told Detective Rahiri that Sumagang had been found sitting11

Prior to the interview , Sumagang was held in a safety cell at the county jail

. When
Detective Rahiri went to the jail, he asked the jail staff to bring out Sumagang so that the
detective could determine whether Sumaga ng was sufficiently coherent to be questioned and whether he was willing to talk. Sumagang appeared able to answer questions accurately and said he was willing to go to the sheriff’s office. Detective Rahiri had Sumagang transported to the Sheriff’s offi ce, where he was handcuffed and placed in an
interview room.
2. Detective Rahiri’s Testimony at the Motion Hearing At the hearing for the motion to suppress, Detective Rahiri testified about the circumstances of the interrogation. Sumagang’s emotions were “kind of up and down,” and sometimes he would cry during the interview, but he appeared to understand the questions at all times. Detective Rahiri maintained a friendly tone and did n ot behave aggressively at any time during the interview. Detective Rahiri testified that he knew Sumagang was in custody, and he confirmed that Sumagang was handcuffed , wearing jail clothes, and not free to leave

. On

cross

- examination, defense counsel a sked Detective R a h iri whether, as a seasoned officer, he knew that when a suspect in custody and about to be question ed about his involvement in a crime, Detective R a h iri was supposed to administer Miranda warnings.
Detective R a h iri responded , “Yes

. ”
D etective R a h iri admitted he “ chose not to ” warn Sumagang under Miranda
because Detective R a h iri “wanted to see what he had to say first.” But w hen defense counsel attempted to question Detective Rahiri specifically about his reasons for not

in the car with Sangc o’s head in his lap. Before interrogating Sumagang, Detective Rahiri questioned Sumagang’s mother and father; obtained the father’s consent to search the car; and obtained consent from the mother to search Sumagang’s bedroom, where Detective Rahiri found medication with Sangco’s name on it. Because this report was not part of the hearing on the motion to suppress, we do not include it in our analysis of this claim

.12

giving Miranda warning s at the start of the interrogation, the prosecution objected repeatedly. First, the prosecut or objected when defense counsel asked Detective Rahiri whether there was any reason not to give Sumagang Miranda warnings at the start of the
interview. The trial court sustained the objection. Defense counsel then asked Detective
Rahiri whether he knew that any incriminating prewarning statements Sumagang made could be used against him for impeachment purposes. The prosecutor objected on the ground that “[t]his goes to the officer, not the defendant.” The trial court sustained the objection. Defense counsel then asked Detective Rahiri whether his purpose for not reading Miranda warnings was to obtain statements that could be used for impeachment. Again, the prosecutor objected , and the trial court sustained the objection. Defense counsel then asked Detective Rahiri whether he was aware of the legal rule allowing for the use of prewarning statements for impeach ment. Again, the prosecutor objected , and the trial court sustained the objection. Defense counsel then asked Detective Rahiri , “So what was your purpose, then, of not reading him his Miranda rights at this critical moment?” The prosecutor objected on r elevance grounds, and the trial court sustained the objection. Finally , when defense counsel asked Detective Rahiri whether he knew “that by asking [Sumagang] questions before Miranda that you were violating his
Miranda rights,” Detective Rahiri responded , “Not at that time, but later on I did.” 5
Detective Rahiri added that he did not come to this realization until “way after the interview” after talking with counsel and thinking about the case

. 3. Pre w arning Portion of the Interrogation
At the start of the prewarning p ortion of the interview, Detective Rahiri told Sumagang that “if at any time you don’t feel like talking, or you wanna leave, just let me know [.

. .] and we’ll end our little discussion. [.

. .] [I]f you wanna leave, you know, we’ll take you back if you don ’ t feel comfortable talkin’ to me. That’s fine. That’s up to

5 The prosecutor objected to this question as well, but the trial court overruled the obje ction.13

you. So this is totally voluntary. You understand? ” Sumagang nodded slightly in
response

. Detective Rahiri asked Sumagang about various personal facts, including his full name, date of birth, driver’s license number, place of residence, employment, and other personal information

. Detective R a h iri then questioned Sumagang about the nature of his relationship s with Sangco and their friends, and the detective elicited a narrative of the events of the night when Sangco d ied

. After about 18 minutes, the subject of the questioning turned to
the circumstances immediately preceding Sangco’s death. Sumagang stated t hat, after the couple drank tequila and swallowed pills, Sangco asked him, “Can you please choke
me out in the back seat please?” He expressly admitted he did so, and he described in detail how and where the two were positioned in the car; how long it las ted; what she said while being choked; how her body reacted; and how she stopped breathing after one or
two minutes. Sumagang also explained how he tried to cut his own wrist with a small knife and attempted but failed to set the car on fire. Finally, De tective Rahiri asked Sumagang about several pieces of evidence that had been found in and around the car. The prewarning part of the interview lasted 25 minutes, followed by a two

- minute break. Upon returning from the break, Detective Rahiri administere d Miranda warnings
and continued the interview for another 45 minutes. After warning Sumagang, Detective Rahiri question ed him in narrative fashion about the events leading up to Sangco’s death.
Detective Rahiri asked about m any of the same topics they h ad covered in the prewarning part of the interview. Detective Rahiri again asked Sumagang to explain how he killed Sangco, what she said when he did so, and how her body reacted as she appeared to go
lifeless.
4. The Trial Court’s Ruling on the Motion to Exc lude
The trial court found the confession was not coerced or involuntary. The court ruled that the prewarning part of the interview was inadmissible except for impeachment
purposes

. As to the postwarning part of the interview, the court ruled it admissible in the14

prosecution’s case in chief. The court found Detective Rahiri’s testimony to be credible
and found “it appears that Detective Rahiri didn’t understand even that he needed to give
the Miranda rights initially

. ” The court added, “I don’t think he was intentionally trying to do anything like that,” and noted that Detective Rahiri’s manner remained calm and
soft

- spoken throughout the interview , consistent with his appearance on the stand. The court further found there was no “softening up” that would have caused Sumagang to
confess. When Sumagang later moved for a mistrial based on the admission of the postwarning statement , the trial court denied the motion. The court relied on Justice Kennedy’s concurring opinion in Seibert in rul ing ag ain that the postwarning statement was admissible. The court again found that Detective Rahiri did not understand that he needed to give Miranda warnings at the start of the interview, and the court found no
deliberate violation of Miranda

. The court fur ther reiterated its finding that the statement was made voluntarily. After the jury rendered its verdict, Sumagang m o ved for a new trial based on
erroneous admission of statements under Miranda

. The trial court denied the motion on the same grounds prev iously set forth.
5. Legal Principles In a custodial interrogation, “ the accused must be adequately and effectively apprised of his rights and the exercise of those rights must be fully honored. ” ( Miranda , supra , 384 U.S. at p. 467.) “[F]ailure to give the prescribed warnings and obtain a waiver of rights before custodial questioning generally requires exclusion of any statements obtained.” ( Seibert , supra , 542 U.S. at p. 608.) “In general, if a custodial suspect, having
heard and understood a full explanation of his or her Miranda rights, then makes an uncompelled and uncoerced decision to talk, he or she has thereby knowingly, voluntarily, and intelligently waived them.” ( People v. Cunningham (2015) 61 Cal.4th 609, 642 .)15

We revi ew independently the trial court’s legal determinations of whether a
Miranda waiver was knowing, intelligent, and voluntary. ( People v. Krebs (2019) 8
Cal.5th 265, 299 ( Krebs ) .) We review the trial court’s factual findings regarding the
circumstances sur rounding the interrogation and waiver under a substantial evidence
standard. ( Ibid. ) The prosecution bears the burden of proof and must show by a preponderance of the evidence the statements were, in fact, voluntary. ( Ibid. )
6. Admission of the Postwarning Statements Was Error
The Attorney General does not dispute that the interview was custodial for the
purposes of the Miranda analysis. Sumagang contends the postwarning portion of the
interview should have been excluded under Seibert , but that even if it was not excludable
under Seibert , it should have been excluded as involuntary. The Attorney General
contends the postwarning portion of the interview was admissible under Oregon v. Elstad (1985) 470 U.S. 298 ( Elstad ).
In Elstad , the police w ent to a suspect ’ s house to arrest him for burglary. The suspect , who had not been warned under Miranda , voluntarily acknowledged he had been
at the scene of the burglary

. Later, a t the start of a systematic , detailed interrogation at the police station, the suspect was warn ed under Miranda , waived his rights , and made a
full confession . ( Elstad , supra , 470 U.S. at pp. 300

- 302.) The high court rejected the argument that the later, postwarning confession was tainted by the earlier statement, and the court held the confession was admissible because it was knowingly and voluntarily made. ( Id. at p. 309.) Following Elstad , i n Sei bert the United States Supreme Court considered a
“two

- step” interrogation in which the police deliberatel y questioned the defendant
without warning h er , issued Miranda warning s , and then continu ed t he interrogat ion

. ( Seibert , supra , 542 U.S. at pp

. 604

- 606.) Seibert feared charges of neglect arising from
the death of her so n, who suffered from cerebral palsy

. In Seibert’s presence, two of her sons and some friends devised a plan to cover up the death by setting fire to the family’s16

mobile home, which also housed a mentally ill teenager. The fire killed the teenager.
Police took Seibert into c ustody and intentionally questioned her for 30 to 40 minutes before giving her Miranda warnings. After she admitted the fire was intended to kill the teenager, police gave her a 20

- minute break, administered the Miranda warnings, and reinitiated the quest ioning, whereupon she repeated the incriminating statements. The questioning officer admitted he made a conscious decision based on his training to withhold Miranda warnings until Seibert confessed

. ( Id. at p. 606.) The trial court granted a motion to suppress the prewarning statements but admitted the postwarning

statements . Seibert was then convicted of second degree murder. The Supreme Court held that such postwarning statements are inadmissible under certain circumstances as se t forth below

. This case is distinguishable from Elstad and much closer to Seibert . Elstad made his postwarning confession in an entirely different interview at the police station, long after his brief prewarning statement at home. Here, as in Seibert , the prewarned statement was given at the sheriff’s office, in response to questioning that was “systematic, exhaustive, and managed with psychological skill.” ( Seibert , supra , 542 U.S. at p. 616.) And as in Seibert , “there was little, if anything, of inc riminating potential left unsaid” after Sumagang gave his prewarning confession. ( Ibid. ) In Elstad , by contrast, the defendant merely admitted in his prewarning statement that he had heard about the burglary and was at the scene of the crime. Finally, t here was nothing in Elstad to suggest the police made a conscious choice to withhold Miranda warnings before questioning the suspect in custody. Here, Detective Rahiri acknowledged that he knew
Miranda warnings are required when questioning a person who i s in custody about their
involvement in a crime and he admitted he chose not to warn Sumagang because he wanted to hear what Sumagang would say first. We conclude that Seibert controls the analysis here.17

Although a majority of the high c ourt in Seibert held that postwarning statements

are inadmissible under certain circumstances, the court was fractured with respect to what circumstances are required or what the test should be. A plurality held that the “threshold
issue” is “whether it would be reasonab le to find that in these circumstances the warnings could function ‘effectively’ as Miranda requires. ” ( Seibert , supra , 542 U.S. at pp. 611

- 612 (plur. opn. of Souter, J.).) The plurality set forth several objective circumstances that
bear on this determi nation, including “the completeness and detail of the questions and answers in the first round of interrogation, the overlapping content of the two statements, the timing and setting of the first and the second, the continuity of police personnel, and
the degree to which the interrogator’s questions treated the second round as continuous with the first.” ( Id. at p. 615.) Justice Kennedy concurred in the judgment but proposed a different test based primarily on the interrogator’s intent . In his view, the postwarning portion of the interrogation would be inadmissible only if “the two

- step interrogation technique was used in a calculated way to undermine the Miranda warning.” ( Seibert , supra , 542 U.S. at p. 6 22 (conc. opn. of Kennedy, J.).) While Justice Kennedy did not explain how such a test would be applied, he noted that the interrogating officer in Seibert “ relied on the
defendant ’ s prewarning statement to obtain the postwarning statement used against her at
trial. The postwarning interview resembled a cross

- examination. The officer confronted the defendant with her inadmissible prewarning statements and pushed her to acknowledge them. ” ( Id. at p. 621.) Furthermore, Justice Kennedy added that “[w] hen an interrogator uses this deliberate, two

- step strategy, predicated upon violating Miranda during an extended interview, postwarning statements that are related to the substance of
p rewarning statements must be excluded absent specific, curative steps .” ( Ibid. ) The California Supreme Court has declined to decide whether the Seibert plurality’s rule or Justice Kennedy’s rule should be applied

. ( Krebs , supra , 8 Cal.5th at p. 309.) T he Attorney General contends Justice Kennedy’s concurring opinion represents18

the holding of the court because it provides the narrowest grounds for supporting the judgment. (See Marks v. United States (1977) 430 U.S. 188, 193 [when a fragmented
court deci des a case and no single rationale is supported by five or more justices , the holding of the court may be viewed as that position taken by the members who concurred in the judgment on the narrowest grounds] ; People v. Camino (2010) 188 Cal.App.4th 1359 ( Camino ). )
We will assume , without deciding, that Justice Kennedy’s concurrence controls the analysis. Accordingly, we consider whether the record shows the two

- step tactic was employed to deliberately circumvent Miranda

. Our analysis of this question, however, is informed by the objective circumstances of the interrogation , including the various
factors set forth in the Seibert plurality opinion

. “[A] trial court must suppress postwarning confessions obtained during a del iberate two

- step interrogation where the
midstream Miranda warning

— in light of the objective facts and circumstances

— did not effectively apprise the suspect of his rights.” ( U.S. v. Williams (9th Cir. 2006) 435 F.3d 1148, 1157 ( Williams ) [confession must be suppressed where law enforcement officers deliberately employ a two

- step interrogation to obtain a confession and where separations of time and circumstance and additional curative warnings are absent or fail to apprise a reasonable person in the suspec t ’ s position of his rights ]. ) The trial court credited the detective’s testimony that he did not believe he was violating Sumagang’s Miranda rights by not giving the warnings at the start of the interrogation. “The trial court had the opportunity to view [the detective’s] demeanor and therefore was in the best position to assess the credibility of” his testimony; we accept
that assessment. ( People v. Coffman and Marlow (2004) 34 Cal.4th 1, 78.) But, regardless of any good faith mistak e at the outset of the interview, at some point Detective Rahiri determined that he needed to give Miranda warnings. The question for this court is whether the government proved by a preponderance of the evidence that, after coming to that realization, the detective “did not deliberately withhold the requisite19

warnings as part of a calculated strategy to foil Miranda .” ( United States v. Guillen (10th Cir. 2021) 995 F.3d 1095, 1121 ( Guillen ).)
The Attorney General ha s not carried that burden. Because the prosecutor objected to defense counsel’s questions of the detective about his reasoning with respect

to Miranda , the record lacks evidence of the detective’s subjective mental processes. “But deliberateness may also be inferred from objective indications o f subjective intent to frustrate Miranda.” ( Guillen , supra , 995 F.3d at p. 1121.) Here, the evidence supports an
inference of deliberateness. First, like the officer in Seibert , Detective Rahiri “relied on the defendant’s prewarning statement to obtain the postwarning statement” in a fashion that “resembled a cross

- examination.” ( Seibert , supra , 542 U.S. at p. 621 (conc. opn. of Kennedy, J.).) In the postwarning part of the interview, for example, Detective Rahiri asked leading questions that incorpora ted incriminating statements Sumagang had only made prewarning. Most significantly, Sumagang made no statements in the postwarning interview about choking or strangling Sangco until Detective Rahiri told him to “explain
the head

- butting” and asked, “ Is th at before you had hands on? ” (Italics added.) When Sumagang responded that he head

- butted her “at the same time as hands on,” Detective Rahiri pressed him to explain, and told him, “So you end up straddling her.” When Sumagang failed to respond , Detecti ve Rahiri added, “She’s face up.” When Sum a gang failed to describe how Sangco was positioned , Detective Rahiri continued to inject f acts elicited in the prewarning part of the intervie w , telling Sumagang, “And then you ’ re on top, hands on

. And how did her body feel? ” As Justice Kennedy observed, “Reference to the prewarning statement was an implicit suggestion that the mere repetition of the earlier statement was not independently incriminating.” ( Ibid. ) (C ompare with Krebs , supra , 8 Cal.5th at p. 31 1 [police did not use defendant’s prewarning statement to induce him to talk after warning him].)
F urthermore , the police did not use any of the “curative measures” suggested by Justice Kennedy’s con currence. ( Seibert , supra , 542 U.S. at p. 622 (conc. o pn. of20

Kennedy, J.).) There was no substantial break in time or circumstances between the two parts of the interrogation, nor any other circumstance that would have “ allow [ed] the accused to distinguish the two contexts and appreciate that the interrogati on ha [d] taken a

new tur n. ” ( Ibid. ) Apart from the Miranda warning s , Detective R a h iri gave no other
admonishments at the start of the postwarning interview, and Detective Rahiri said nothing that would have informed Sumagang his prior statement still could not be used against him even if he chose to remain silent at that point. The fact that “[n]o curative steps were taken,” weighs in favor of exclusion under Justice Kennedy’s concurrence. ( Ibid. ) Finally , we note that, as in Justice Kennedy’s concurrence, the use of a two

- step interrogation here, whether deliberate or otherwise, did not serve any legitimate purpose. Our analysis is informed by the objective factors set forth in the Seibert plurality opinion. (See Williams , supra, 435 F.3d a t pp. 1157

- 1158 [ in determining whether the interrogator deliberately withheld the Miranda warning, courts should consider whether objective evidence and any available subjective evidence, such as an officer ’ s testimony, support an inference that the two

- s tep interrogation procedure was used to undermine the
Miranda warning ].) The first factor

— the completeness and detail of the questions and answers in the prewarning interview

— weighs in favor of exclusion. Over the course of
the 25

- minute interview, Detec tive Rahiri elicited a detailed narrative of the night that Sangco died, including all the facts needed to inculpate Sumagang. Sumagang stated that after the couple drank tequila and swallowed pills, Sangco asked him, “Can you please
choke me out in the b ack seat please?” He expressly admitted he did so, and he described in detail how and where the two were positioned in the car; how long it lasted; what she said while being choked; how her body reacted; and how she stopped breathing after one
or two minu tes. The prewarning statement thereby provided detailed evidence about the
nature of the offense.
The second factor

— the overlapping content of the two statements

— also weighs in favor of exclusion. As set forth above in section I.B.3., Detective Rahiri elicited the same21

basic narrative of the night’s events in the postwarning interview, and Sumagang confessed again that Sangco asked him to kill her. Similar to his statement in the prewarning portion of the interview, Sumagang admitted in the postwarning portion that “I gave it to her” and he admitted he had his “hands on” her, whereupon her eyes started shuttering, her arms started going limp, and her body stopped moving. The remaining factors

— the timing a nd setting of the first and the second parts, the continuity of police personnel, and the degree to which the interrogator’s questions
treated the second round as continuous with the first

— further weigh in favor of exclusion. The setting consisted of the same room for both parts of the interview, the same interrogator conducted both parts, and the postwarning questioning started two minutes after the prewarning portion of what amounted to a continuous interaction between the detective and the suspect. Det ective Rahiri began the prewarning part of the interview by gathering various facts about Sumagang’s personal background, but when he returned for the postwarning part, he directed the questioning to the events of the fatal evening. Detective Rahiri then questioned Sumagang about the same critical facts of the choking. As in Seibert , “The impression that the further questioning was a mere continuation of the earlier questions and responses was fostered by references back to the confession already given.” ( Seibert , supra , 542 U.S. at p. 616.) Viewing these factors together with Detective Rahiri’s testimony , and considering the overall setting and context of the interrogation, we conclude the detective deliberately
undermine d Miranda by employing the two

- s tep interrogation tactic. Even considering
the Seibert plurality’s test by itself, however, it would not be reasonable to find the
Miranda warnings objectively functioned effectively as required. A reasonable person in Sumagang’s position at the start of the postwarning interview would not have thought he had “a real choice about giving an admissible statement at that juncture” or that he could “choose to stop talking even if he had talked earlier.” ( Seibert , supra , 542 U.S. at pp.
611

- 612.) There was n o “practical justification for treating the second stage of22

interrogation as distinct from the first, unwarned and inadmissible segment. ” ( Id. at
p. 612.) We therefore conclude th e two

- stage interrogation violated the standards set
forth in both Justice Kennedy’s concurrence in Seibert as well as the Seibert plurality’s opinion. The interrogation in this case is distinguishable from the questioning considered by the California Supreme Court in Krebs , supra , 8 Cal.5 th 265. Krebs was convicted of two first degree murders, forcible rape, sodomy, kidnapping, and other offenses. ( Id. at pp. 273

- 274.) He was on parole at the time of the offenses, and he was taken into custody for a parole violation before police had conn ected him to the murders. While he was in custody, police questioned him several times about whether he was involved with the murders, but he initially denied it. He was one of 13 to 16 persons being questioned by the police for the killings. ( Id. at p. 295.) Police did not initially administer Miranda warnings, but Krebs was warned prior to the second interview. At the start of the fourth such interview, before the officer administered Miranda warnings, Krebs told the officer,

“ ‘ I ’ m nothing but an an imal. I don ’ t deserve to live ’ and ‘ Nothing can justify what I
did. ’ ” ( Id. at p. 298.) After the interrogating officer administered Miranda warnings, Krebs confessed to the killings in detail. ( Id. at pp. 294

- 295.) The trial court excluded
the statem ents made before the warnings but admitted the confession. The Supreme Court held the postwarning statements were properly admitted under either the plurality’s approach in Seibert or Justice Kennedy’s concurrence. ( Krebs , supra , 8 Cal.5th at pp. 309

- 312 .) Applying the plurality’s test, the court noted there was no extended questioning before the Miranda warnings; the defendant’s prewarning responses were vague and nonspecific; and there was a change of setting before he made the confession. Moreover, p rior to the confession, the questioning officer administered
the Miranda warnings in a detailed way that informed defendant he had a “real choice” whether to follow up on his earlier statements. Applying Justice Kennedy’s test, the court concluded the que stioning officer did not deliberately undermine the Miranda23

warnings. Most significantly, the court noted that the officer administered the Miranda warnings before Krebs confessed. ( Id. at p. 311.) The court also credited the officer’s testimony that Krebs was not in custody for the killings. All of these factors distinguish Krebs from this case. Here, the officer did not warn Sumagang until after he confessed in great detail. Second , there was no doubt Sumagang was in custody for the death of Sangco, and not for any other reason. Third, there was no change of setting before the prewarning and postwarning portions of the interview. Fourth, Sumagang was not given Miranda warnings at any time prior to his prewarning interview.
T he Attorney General argues that Sumagang was not under arrest at the time of the interrogation and that Detective Rahiri did not yet consider Sumagang to be a suspect in
the crime. The record does not support the Attorney General’s contention. Detective
Rahiri , who was the lead detective on the case, was aware of the evidence found at the scene of the crime, and he was told by another detective that Sumagang was found with Sangco’s body in his lap. Then, t hro ughout the postwarning interview , he confronted Sumagang with photographs of the evidence and questioned him about the various pieces
of evidence , including injuries to Sangco’s body

. There were no other suspects at the
scene of the crime

— only Sumagang, w ho was discovered with Sangco lying i n his lap. At no point did Detective Rahiri identify any other person he would have considered to be a suspect. And there is no dispute that Sumagang was in custody for the offense;
whether he was formally “under arre st” or not, it was abundantly clear that Miranda warnings were required. The Attorney General relies on Camino , supra , 188 Cal.App.4th 1359. Camino concerned the interrogation of a former gang member who was involved in a fatal shooting during a shoot

- out with a rival gang. ( Camino , at pp. 1364

- 1367.) Camino was not the shooter. Rather, the victim of the shooting was Camino’s fellow gang member,

w ho was shot after Camino and another person chased down members of the rival gang.24

The prosecution later charged Camino under the “provocative act” doctrine. Under this doctrine, a defendant may be charged in the death of an accomplice if the defendant

c ommits a provocative act that provokes a third party into killing the accomplice. After the shooting, the police interviewed Camino twice

— first without Miranda warnings, during which Camino gave a detailed account of the shooting

— and then again
30 minut es later after issuing the warnings, after which the interview covered the same basic facts. At an evidentiary hearing on the defendant’s motion to suppress, the questioning officer testified that his department did not have a policy of administering
thes e two

- step interrogations, and he asserted he did not intentionally withhold Miranda warnings to obtain inculpatory statements in the first part of the interview. ( Camino , supra , 188 Cal.App.4th at p. 1374.) The officer testified that he did not know whe ther
Camino was a witness, victim, or suspect in the case before initiating the first part of the interview. During the prewarning part of the interview, the officer realized that Camino might have some criminal culpability, whereupon the officer stopped the interview and
administered the Miranda warnings before interviewing Camino again. The trial court ruled that the postwarning part of the interview was admissible because the officer did not deliberately use a two

- step process to circumvent Miranda

. T he Court of Appeal in Camino affirmed the conviction. ( Camino , supra , 188 Cal.App.4th at p. 1382.) The court held substantial evidence supported the trial court’s finding that the officer did not deliberately use a two

- step process. ( Id. at p. 1376.) T he court noted that at the start of Camino’s interview, the police did not know the circumstances of the shooting, and they did not know whether Camino was even present when the victim was shot. Relying on Justice Kennedy’s concurrence in Seibert , the

cou rt concluded the postwarning portion of the interview was admissible. The Camino court held that Justice Kennedy’s concurrence represented the holding of Seibert under
the Marks rule. ( Id. at p. 1370.)25

T his case is distinguishable from Camino , in which the defendant’s involvement in the shooting was more peripheral, and the police had a credible explanation for why they
did not know if Camino was present at the shooting when they began the interview. ( Camino , sup ra , 188 Cal.App.4th at pp. 1374

- 1375.) Here, Sumagang was the sole suspect in Sangco’s death, and the police had abundant evidence of his involvement. For the reasons above, we conclude the trial court erred by admitting Sumagang’s postwarning statements under Miranda and Seibert

. Admission of the statements
constituted a violation of the Fifth and Fourteenth Amendments.
7. Admission of the Postwarning Statement Prejudiced Sumagang The Attorney General bears the burden of showing that admission of the postwarning confession was harmless beyond a reasonable doubt. ( Arizona v.
Fulminante (1991) 499 U.S. 279, 296 ( Fulminante ), citing Chapman v. California (1967) 386 U.S. 18.) “ ‘The beyond

- a

- reasonable

- doubt standard of Chapman “requir[es] the beneficiary of a [federal] constitutional error to prove beyond a reasonable doubt that the error complained of did not contribute to the verdict obtained.” [Citation.] “To say that an error did not contribute to the ensuing verdict is

. . . to find that error unimportant in relation to everything else the jury considered on the issue in question, as revealed in the record.” [Citation.] Thus, the focus is on what the jury actually decided and whether the error might have tainted its dec ision. That is to say, the issue is “whether the

. . . verdict actually rendered in this trial was surely unattributable to the error.” ’ ” ( People v.
Pearson (2013) 56 Cal.4th 393, 463.)
With respect to the erroneous admission of a confession, the burd en under the Chapman standard is difficult to satisfy . “ T he defendant’s own confession is probably the most probative and damaging evidence that can be admitted against him.

. . . [T]he admissions of a defendant come from the actor himself, the most know ledgeable and unimpeachable source of information about his past conduct. Certainly, confessions have26

profound impact on the jury, so much so that we may justifiably doubt its ability to put them out of mind even if told to do so.” ( Fulminante , supra , 49 9 U.S. at p. 296.) The Attorney General argues that even apart from the confession, strong evidence showed Sumagang killed Sangco with premeditation and deliberation. The Attorney General points to Sumagang’s statement s at the scene of the crime ; the tes timony of the prosecution’s forensic pathologists; and the physical evidence found in and around the

car. First, as to Sumagang’s own statements at the scene of the crime , they were vague and incomplete. He was crying, and according to police, he told th em “he was not supposed to be there” and was “supposed to be with t he female. ” H e said he and Sangco had both “taken a bunch of Klonopin and drank as much tequila as the y could

. ” One police officer testified that Sum a gang “mentioned that he did this to her , ” and another officer testified that when he asked Sumagang how Sangco received injuries to her face, Sumagang replied, “I did that to her.” These statements showed that Sumagang injured Sangco, but not that he killed her in a premeditated fashion.
T he forensic pathologists who testified for the prosecution opined that Sangco had been choked or strangled to death, but Sumagang’s expert witness disputed th eir
conclusions

. Both sides’ experts agreed there were no internal injuries in Sangco’s neck.
Th e toxicology report showed Sangco had a potentially toxic level of methamphetamine
in her blood , as well as cocaine

. The prosecution’s witnesses relied primarily on the presence of petechiae on Sangco’s face, but Sumagang’s expert testified that the petec hiae were scattered and none were large. Sumagang’s expert testified that Sangco could have died from a drug overdose and opined that any petechiae could have been caused by chest compressions during CPR or as the result of a non

- fatal choking attempt

. A reasonable jury could have credited that testimony. The Attorney General offers nothing to show beyond a reasonable doubt that t he jury relied on the prosecution’s experts rather than Sumagang’s confession to conclude he killed her.27

Even if the jury cre dited the prosecution’s experts in finding Sangco died of choking o r strangulation, the evidence did not establish beyond a reasonable doubt that Sumagang intentionally killed Sangco with premeditation

. The Attorney General points to physical evidence showing that the car had been set on fire, but absent Sumagang’s confession, there was no other evidence he set the fires instead of Sangco or someone
else. The Attorney General points to the injuries on Sangco’s face and Sumag ang’s own face, but both sides’ experts agreed that Sangco did not die from th ose injuries. Absent Sumagang’s confession, the remaining evidence was not so overwhelming that it would have resulted in a guilty verdict o f first degree murder beyond a reason able doubt. To the contrary, it is reasonably likely the jury relied at least in part on Sumagang’s confession in finding he intentionally killed Sangco with premeditation. Accordingly, we must reverse the judgment of conviction

. B. Other Claims Sumagang r aised several other claims in this appeal. He contends the trial court erred by admitting his postwarning statements regardless of whether it was admissible
under Seibert because his confession was involuntary. Second, he contends the court erred by fail ing to instruct the jury on voluntary intoxication. Third, he argues the cumulative effects of those errors requires reversal. Finally, he contends we should conditionally reverse the judgment and remand for a mental health diversion eligibility hearing under Penal Code section 1001.36. Because we are reversing the judgment of conviction, we do not reach these additional claims.
III. D ISPOSITION The judgment is reversed

._______________________________ Greenwood, P. J.

WE CONCUR:

______________________________________ Elia, J.

_____________________________________ Danner, J.

People v. Sumagang No. H 04402 3Trial Court: Monterey County Superior Court Superior Court No.: SS143024 Trial Judge: The Honorable Carrie McIntyre Panetta

Attorney for Defendant and Appellant Patrick McKenna Byron Silim Sumagang: under appointment by the Court of Appeal for Appellant

Attorneys for Plaintiff and Respondent Rob Bonta, The People: Attorney General of California Gerald A. Engler Chief Assistant Attorney General Jeffrey M. Laurence Senior Assistant Attorney General

Donna M. Provenzano Supervising Deputy Attorney General

Victoria Ratnikova Deputy Attorney General

People v. Sumagang H044023