Filed 10/14/21 (unmodified opn. attached)

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)

ORDER MODIFYING OPINION

 AND DENYING PETITION FOR

 REHEARING

 NO CHANGE IN JUDGMENT

The Attorney General’s petition for rehearing is denied as moot. The court orders 

that the opinion filed September 29, 2021, be modified as follows:

The first sentence of the first full paragraph on page 19 of the opinion shall be 

deleted and replaced with the following: “The record does not hold substantial evidence 

to show the prosecution carried its burden.”

There is no change in the judgment.

 ___________________________

 Greenwood, P. J.

_____________________________ ___________________________

 Elia, J. Danner, J.
Filed 9/29/21 (unmodified opinion)

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 withheld 

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, defendant Byron Silim Sumagang confessed that he killed his 

girlfriend as part of a botched double-suicide attempt. After the postwarning statements

were 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 conviction.1

1 Sumagang raises other claims as set forth in section II.B., but we do not reach 

those claims.
2

I. FACTUAL AND PROCEDURAL BACKGROUND

The police 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 interviewed 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 breathing 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 “potentially 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 Monterey 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. Sangco 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 they could” the previous evening. The deputy testified that

Sumagang told her he was “not supposed to wake up,” and he was “supposed to be with 
3

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, and 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 been stuffed into the neck of the gas tank. A shoeprint was 

found near the crack in the front windshield. 

B. Postwarning Confession

Police interrogated Sumagang about two days after taking him into custody. The 

postwarning 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 his own wrists 

and neck. 

At some point after they parked, Sumagang tried to set the car on fire 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 kicking 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 injuries to her head, Sumagang said he 

“[p]robably head-butted her” at the same time he had his “hands on” her. Sumagang said 
4

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, “ ‘Please, give it to me. 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, because . . . . [. . .] 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 her conclusions about the 

cause of death, she was “informed thoroughly” by the coroner’s detectives about 

Sumagang’s statements, and she 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 also 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 she observed multiple external 

injuries to Sangco’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 lip; 

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. The external injuries were 

the result of blunt force trauma. Sangco also had a postmortem tooth impression 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 

compression 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 and they start to 

rupture and they cause these little dot-like hemorrhages.” 

Dr. Azar testified that Sango had injuries 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, 

big 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 tell me. I need someone 

else to tell me. And she had these scratches to her neck. Those are worrisome 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 she had been told, Dr. Azar concluded that the 

cause of death was asphyxiation due to smothering with manual strangulation. She 

determined that the 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 not believe the petechiae 

were caused by the medics’ resuscitation efforts.

Dr. Azar also ordered toxicology tests of Sangco’s blood. She testified that 

Sangco tested positive for methamphetamine and cocaine, but these results did not 

change Dr. Azar’s opinion 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 from 

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 strangulation cases, “because of pressure on the neck, 

there’s often forcing—there’s a forcing of the tongue, tip of the tongue, between the teeth 
7

and with the upper—usually upward pressure on the jaw during strangulation, there are 

often bite mark hemorrhages or bruises 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 

observed 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, he had seen other cases of strangulation with no external markings on the neck. 

Dr. Joseph Cohen testified for the defense as 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 connect 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 paramedics. 
8

He had observed many cases in which neck 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 Sangco could have caused the 

petechiae in Sangco, 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 testified that head trauma did not cause or contribute 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, was 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 death. 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 Sangco died of a drug overdose five or 20 minutes after 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 violently toward Sangco 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 Sangco 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 mad. 

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 windshield in the car

Sumagang and Sangco were in. Sumagang and Sangco had been mad at each other 

earlier. Sangco was throwing socks at Sumagang, and he threw a cup toward her but did 

not hit her. Luna never saw Sumagang physically abuse Sangco or put his hands 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. Sangco 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 Sangco 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 suicide. Sangco appeared more stable and hopeful after 

being released, but she stopped attending appointments by October 2013.

II. DISCUSSION

A. Admission of the Postwarning Part of the Interview

A detective interviewed Sumagang in two stages—before administering

Miranda2warnings, 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 hearing at which the 

detective, Terry Rahiri, testified about the circumstances of the interrogation as set forth 

below. The trial court excluded the prewarning 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 properly 

admitted it because the interview was voluntary and the detective did not intentionally 

undermine the Miranda warnings. For the reasons below, we conclude the trial court 

erred by admitting the postwarning portion of the interview.

1. Circumstances Preceding the Interrogation

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 big 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 preserve 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 report, 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 sitting 
11

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 Sumagang 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 office, 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 not 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 asked Detective Rahiri whether, as a seasoned 

officer, he knew that when a suspect in custody and about to be questioned about his 

involvement in a crime, Detective Rahiri was supposed to administer Miranda warnings. 

Detective Rahiri responded, “Yes.”

Detective Rahiri admitted he “chose not to” warn Sumagang under Miranda

because Detective Rahiri “wanted to see what he had to say first.” But when defense 

counsel attempted to question Detective Rahiri specifically about his reasons for not 

in the car with Sangco’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 warnings at the start of the interrogation, the prosecution objected 

repeatedly. First, the prosecutor 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 impeachment. 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 relevance 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. Prewarning Portion of the Interrogation

At the start of the prewarning portion 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 

objection.
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 Rahiri then questioned Sumagang about the nature of his relationships

with Sangco and their friends, and the detective elicited a narrative of the events of the 

night when Sangco died. After about 18 minutes, the subject of the questioning turned to 

the circumstances immediately preceding Sangco’s death. Sumagang stated that, 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 lasted; 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, Detective 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 administered Miranda warnings 

and continued the interview for another 45 minutes. After warning Sumagang, Detective 

Rahiri questioned him in narrative fashion about the events leading up to Sangco’s death. 

Detective Rahiri asked about many of the same topics they had 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 Exclude

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 the 
14

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 ruling again 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 further reiterated its finding that the statement 

was made voluntarily. 

After the jury rendered its verdict, Sumagang moved for a new trial based on 

erroneous admission of statements under Miranda. The trial court denied the motion on 

the same grounds previously 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 review 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 surrounding 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 went 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, at the start of a systematic, detailed interrogation at 

the police station, the suspect was warned 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, in Seibert the United States Supreme Court considered a

“two-step” interrogation in which the police deliberately questioned the defendant 

without warning her, issued Miranda warnings, and then continued the interrogation. 

(Seibert, supra, 542 U.S. at pp. 604-606.) Seibert feared charges of neglect arising from 

the death of her son, 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’s 
16

mobile home, which also housed a mentally ill teenager. The fire killed the teenager. 

Police took Seibert into custody 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 questioning, 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 set 

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 incriminating 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, there 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 is 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 court 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 reasonable 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 determination, 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. 622 (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 

prewarning 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.) The Attorney General contends Justice Kennedy’s concurring opinion represents 
18

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 decides 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 deliberate 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 suspect’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 mistake 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 requisite 
19

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 has 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 of 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 incorporated 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 that 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, Detective Rahiri added, “She’s face up.” When Sumagang 

failed to describe how Sangco was positioned, Detective Rahiri continued to inject facts

elicited in the prewarning part of the interview, 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.) (Compare with Krebs, 

supra, 8 Cal.5th at p. 311 [police did not use defendant’s prewarning statement to induce 

him to talk after warning him].)

Furthermore, the police did not use any of the “curative measures” suggested by 

Justice Kennedy’s concurrence. (Seibert, supra, 542 U.S. at p. 622 (conc. opn. of 
20

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 interrogation ha[d] taken a 

new turn.” (Ibid.) Apart from the Miranda warnings, Detective Rahiri 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 at 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-step 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, Detective 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 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 lasted; what she 

said while being choked; how her body reacted; and how she stopped breathing after one 

or two minutes. 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 same 
21

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 and 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. Detective 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 

undermined Miranda by employing the two-step 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 no “practical justification for treating the second stage of 
22

interrogation as distinct from the first, unwarned and inadmissible segment.” (Id. at 

p. 612.) We therefore conclude the 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.5th 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 connected 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 animal. 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 statements 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, prior 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 questioning officer did not deliberately undermine the Miranda
23

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.

The 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, throughout 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, who was discovered with Sangco lying in 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 arrest” 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, 

who 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 

commits 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 minutes 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 

these 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 whether 

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.

The 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.) The 

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 

court 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

This 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, supra, 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 decision. 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 burden under the

Chapman standard is difficult to satisfy. “The 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 knowledgeable and 

unimpeachable source of information about his past conduct. Certainly, confessions have 
26

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, 499 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 statements at the scene of the crime; the testimony 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 them “he was not 

supposed to be there” and was “supposed to be with the female.” He said he and Sangco 

had both “taken a bunch of Klonopin and drank as much tequila as they could.” One 

police officer testified that Sumagang “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.

The forensic pathologists who testified for the prosecution opined that Sangco had 

been choked or strangled to death, but Sumagang’s expert witness disputed their

conclusions. Both sides’ experts agreed there were no internal injuries in Sangco’s neck.

The 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 

petechiae 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 the jury relied on the prosecution’s 

experts rather than Sumagang’s confession to conclude he killed her.
27

Even if the jury credited the prosecution’s experts in finding Sangco died of 

choking or 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 Sumagang’s own 

face, but both sides’ experts agreed that Sangco did not die from those injuries.

Absent Sumagang’s confession, the remaining evidence was not so overwhelming 

that it would have resulted in a guilty verdict of first degree murder beyond a reasonable 

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 raised 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 failing 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. DISPOSITION

The judgment is reversed.
_______________________________

Greenwood, P. J.

WE CONCUR:

______________________________________

 Elia, J.

_____________________________________

 Danner, J.

People v. Sumagang

No. H044023
Trial 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