In late August of 2013, Ryan Hoy called the Aurora Colorado Police Department for help. He said that his wife, 47-year-old Yun-Mi, and his 18-year-old stepdaughter, Isabella, were locked in the upstairs bathroom. He could hear his wife yelling for help, but wasn’t sure exactly what was going on. Then, he saw blood start to seep underneath the bathroom door and into the hallway. Shortly after, Isabella opened the bathroom door, knife in hand and covered in her mother’s blood, and walked down the stairs and out of the home. What could’ve caused the young girl to commit such a brutal act? Was she suffering from delusions and an untreated mental illness? Or was she simply a master manipulator?
Who is Isabella?
Isabella Guzman was born on June 9th, 1995 to father, Robert Guzman and mother, Yun-Mi Hoy. Eventually Robert and Yun Mi divorced when Isabella was three years old. Her mother remarried to a man named Ryan Hoy, and her father eventually remarried as well. There isn’t much published about Isabella as a child, but she struggled with behavioral issues from a young age. When she was just seven years old, Yun-Mi sent Isabella to go live with her father, Robert, because she couldn’t handle her behavior.
Though living apart initially alleviated some of the issues between Isabella and her mother, when she eventually returned to live with Yun-Mi and her stepfather, Ryan, around the age of 14, the friction returned and it was worse than ever. Ryan later described his stepdaughter as “hot-tempered”, someone who ran her mouth a lot, cursing at her parents. She was very resentful towards her mother and the two often had loud verbal altercations with one another. Ryan said that his wife would argue back with Isabella, which would only enrage Isabella more.
Ryan later told investigators that Isabella had been seen by a psychiatrist once, when she was about 16 years old, but that the doctor said she was a typical teenage girl. They were concerned about her behavior, her attitude, and her eventually dropping out of Overland High School, but the psychiatrist didn’t share their concerns.
On Tuesday, August 27th, 2013, it was reported that Isabella’s disdain for her mother had reached a new height. The two had gotten into an argument, and Isabella had yelled at Yun-Mi and spit in her face. Yun-Mi was so upset by her daughter’s behavior, and so scared for her own well-being that she asked Ryan to sleep in her room with her that night (seems like the two normally just slept in different bedrooms).
The following day, Wednesday, August 28th, Yun-Mi showed Ryan an email on her cell phone. The email was from Isabella, but it wasn’t addressed to Yun-Mi. It was addressed to a “Cecilia”. The exact contents of the email have never been released, however Ryan said that it was threatening and said, “you will pay”. Yun-Mi, still upset by Isabella’s behavior and the email, ended up calling the Aurora Police Department because she was so concerned for her own safety.
Four officers responded to the family home on South Lima Drive in Aurora, Colorado, along with Isabella’s birth father, Robert. They all spoke in the backyard, where the officers told Isabella that she had to respect her mother. They even told her that her mother had the right to file for a motion to evict her from the home if she felt it was necessary, since Isabella was 18 years old.
After the officers left, Robert stayed and spoke privately with his daughter, telling her that she had to understand the importance of respecting her parents, especially her mother. Robert later said that he thought that it was a really good conversation, that he thought his daughter was finally understanding and that he’d gotten through to her.
Ryan later said that after the situation, Isabella seemed fine. He clarified that it was clear she was upset at her mother for calling the police, but that nothing seemed abnormal. Ryan was absolute—there was no indication of what was to come that night.
The Day of the Murder
On Wednesday, August 28th, around 9:30 PM, Yun-Mi returned home. After she’d called the police earlier that day because of Isabella’s increasingly concerning behavior, Yun-Mi had returned to work at her photography studio. This was the same studio that she’d gotten Isabella a job at, hoping it would help her learn responsibility.
Yun-Mi brought a bag of McDonald’s home with her for Ryan. He said that when she arrived home, she asked where Isabella was, but he wasn’t sure. He’d last seen her in the kitchen about an hour ago. Ryan stayed in the living room to eat his dinner, while Yun-Mi went upstairs to take a shower.
After a few minutes, Ryan heard thumping noises, loud, that seemed to shake the whole house. He then heard his wife screaming his name. Ryan ran upstairs and found the noise and screams coming from the bathroom. He heard the shower running and the door was just slightly ajar. When Ryan tried to enter the room, Isabella leaned back against it, locking it. He tried to push against it, but couldn’t get inside.
Ryan ran back downstairs to the living room to grab his cell phone and call 911. At 10:05PM, the Aurora Police Dispatch Center received their second call of the day from 2624 South Lima Street. Roy told the dispatcher that his wife and stepdaughter were inside the bathroom and that he couldn’t get inside. He said that he thought his wife was seriously injured and that he could see blood coming from underneath the door.
Ryan then heard his wife say, “Jehovah”, then Isabella opened the bathroom door. She stood in the doorway, holding a knife in her right hand. Ryan described his stepdaughter as having a blank look on her face as she stared straight ahead, then walked right past him.
He walked into the bathroom and saw Yun-Mi laying on the floor, covered in blood. There was a baseball bat underneath her. The dispatcher instructed Ryan on how to open his wife’s airway and perform CPR. Ryan did as told, but later said that he believed his wife was already dead because of the blank look in her eyes.
At 10:16PM, officers arrived at the home to find Ryan, now covered in blood. Ryan told the officers that Isabella had fled the residence, wearing a pink sports bra and turquoise shorts. After quickly clearing the residence of any threats, officers found Yun-Mi lying nude in the bathroom on her back. She had a significant amount of lacerations to her face and neck. Paramedics arrived shortly afterwards and pronounced Yun-Mi dead at 10:28PM. Isabella was nowhere to be found.
The Search
The Aurora Police Department immediately began a search to find 18-year-old Isabella. They attempted to ping her cell phone, but it had been turned off. Around 11:30 AM the next day, Thursday, August 29th, officers received a call regarding a body inside of a vehicle in a parking garage on South Parker Road, just about 8 miles or so from the Hoy residence.
When they arrived, the caller told them that he’d seen a person sitting inside a Jeep that belonged to his company. On the ground outside of the Jeep was a backpack and a bunch of clothes. Nobody was inside the vehicle. Concerned with some of the items found on the ground, the responding officer called in for backup and the parking garage was searched. More items were found that concerned officers that they might be connected to the murder of Yun-Mi.
Witnesses said that eventually, a woman walked out of the garage with several officers. Isabella had been found hiding underneath a staircase. A bloody knife was found nearby. She was taken into custody and investigators began what soon became one of the most frustrating interrogations they’d ever been in.
The Interrogation
As Isabella Guzman sat inside of a police interrogation room, two detectives couldn’t even get her to answer the most basic of questions. She vehemently denied being Isabella Guzman. In fact, she claimed that her name was Samantha Gonzalez and that she was just 15 years old. She accused the officers of trying to ruin her life because she looked similar to someone named Isabella.
Isabella asked them to fingerprint her multiple times, desperate to prove that she wasn’t this murderer they’d been looking for. As the detectives insisted that it was obvious she was, in fact, Isabella Guzman, the young girl continued to argue, saying that Isabella was supposedly 110 pounds, which was much thinner than she was…she said that she was 148 pounds.
The detectives showed her photos of Isabella, clearly showing that she was her, however she said that there were a lot of people in the world who looked the same. As for why she was in the parking garage that day, Isabella told them that she’d ran away from an abusive mother. She said her mother, Sabrina, hated her because she was her illegitimate child and that she’d never met her real father. She only knew that her father was Mexican and that his last name was Gonzalez. She continued to tell investigators that she wished she’d never taken that shortcut through the parking garage.
Isabella continued to ask the detectives to fingerprint her or to take her DNA, that they wouldn’t match with this murderer that they were looking for. Detectives told her that she’d be spending the rest of her life in jail for what she did. Every time they called her Isabella, she’d tell them to stop calling her that, that her name was Samantha.
Isabella told the detectives that she lived in Cincinnati, Ohio and went to Montgomery High School. The home address she gave officers didn’t exist in Cincinnati, but it did exist in Aurora, just across the street from where Isabella lived with her mother and stepfather. When confronted with this information, Isabella really didn’t have a response.
When asked where she was supposedly running away to, Isabella told detectives that she was meeting her boyfriend and that he was probably really worried about her. Isabella said that his name was Gabriel Adams and that they could call him and clear all of this up. Unfortunately, she didn’t know how to reach him because he’d had to “dump” his cell phone.
Despite the continued interrogation and all of the irrefutable evidence being presented to Isabella, she remained steadfast in her denials. Her affect was extremely flat and nothing really seemed to upset her. She denied any drug or alcohol use, and said she’d never been to see a doctor for anything other than the occasional cold. Detectives knew this wasn’t true, they’d found marijuana in Isabella’s bedroom (which, by the way, was the master bedroom of the house) and spoke to some of the people who knew her.
When detectives told Isabella that they’d talked to her friends, she said that she didn’t really have any friends. The detectives told her that most of the people they’d spoken to didn’t really like her and thought she was mean and a liar. This was one of the first things that seemed to rock her during questioning.
One of the people brought in by police for questioning was a friend of Isabella’s, Catherine “Cathy” Argueta. Cathy and her boyfriend used to spend much of their free time with Isabella and her now-ex-boyfriend, Ilya (ill-ee-yuh). The foursome used to smoke weed together. Cathy said that Isabella had recently developed a spiritual side, but had become much more withdrawn since she began dating Ilya. However, on August 26th, two days before the murder, Cathy received a text message from Isabella. The text was insulting and derogatory, and also said, “I know what you did”. Cathy immediately responded, asking Isabella what she was talking about, but she got no response.
On August 28th, the day of the murder, Cathy received another strange text from Isabellla around 7:15PM. The text said, “The astro beam has awakened”. Cathy again responded, asking her what she was talking about, but Isabella didn’t text back. Just a few hours later, she’d brutally murdered her mother.
Cathy said that she’d never known Isabella to be violent. At first, she thought that Isabella had just beaten her mother up, and that was shocking enough. When she learned that Isabella had actually stabbed her mother to death, she couldn’t believe it.
A young man named Darrian said that he’d known Isabella for a while, but, like her friendship with Cathy, had only hung out with her sporadically. He said that when they had hung out, Isabella usually came from her house and was upset about something her mother had done. He also said that he’d seen Isabella experiment with harder drugs, like morphine, and that he’d even seen her physically assault a girl while high on morphine. Also similar to Cathy’s account, Darrian said that when he first met Isabella, she was talkative and fun, but recently, she’d become really withdrawn and emotionless.
Ryan told investigators that Isabella had dated Ilya for a few years, but that she’d broken up with him a few days before the murder. Prior to their breakup, Isabella spent all of her time with Ilya. Ryan said that if Isabella wasn’t with Ilya, she was in her bedroom with the door shut. After the breakup, Isabella had instructed her stepfather not to let Ilya in the house. However, on the afternoon before the murder, Ilya came by the house and ducked inside to grab something that he said he’d left in Isabella’s bedroom, then left. Ryan didn’t think much of it.
Ilya said that he’d come by the house a few days prior to the murder to return some of her belongings, and that she’d opened the door angrily and tried to attack him with a golf club. Ilya said that Isabella had broken up with him after accusing him of cheating on her with Cathy, which he denied. He also said that after the breakup, Isabella continued to text Ilya threats and accusations.
He also told them that Isabella was convinced that her mother had tried to poison her and the dogs. She’d told Tony (Ilya) that she’d gotten really sick after eating something from the refrigerator and that she’d smelled bleach in the dog’s water bowl. Though Tony had seen many verbal arguments between Isabella and Yun-Mi, he’d never seen it get physical.
Detectives talked to Isabella’s stepfather, Ryan, who couldn’t really comprehend what had happened. Despite the resentment and hostility Isabella clearly had for her mother, Ryan said that he never would’ve imagined she’d do something like this. He said that Isabella’s anger had increased over the past few weeks, but couldn’t think of anything specific that prompted it. Ryan described his stepdaughter as being extremely depressed about her life and said that she seemed to blame her mother for everything.
Ryan couldn’t recall ever having seen his wife and stepdaughter in a physical fight, but had witnessed countless verbal altercations. He described how Isabella would scream at Yun-Mi and that Yun-Mi would often yell back. When asked if he ever intervened in the arguments, Ryan said that he’d learned over the years that the best course of action was for him to stay out of it and let Yun-Mi handle it.
Ryan also told them about a time about five years ago when Isabella had come down to the basement, where he slept, to borrow his fan. When he told her that she couldn’t have it, Isabella punched him in the face. She was used to getting her way in the home, and even had the master bedroom as her own. She had four dogs that lived in the house, and some said that Isabella essentially ran the household. She burned incense constantly, (probably to cover up the smell of her smoking marijuana in her bedroom) which really irritated Yun-Mi.
Unsurprisingly, this wasn’t the first time Isabella had a run-in with the police, although this was clearly more severe. Ryan said that she’d gotten in trouble in the past for shoplifting, trespassing, and drinking alcohol at school. She’d even been expelled in the past for bringing a knife to school about three years prior to the murder.
They asked him about when he’d found Isabella in the bathroom with Yun-Mi. Ryan said that he could hear loud noises, that he thought Isabella was striking Yun-Mi with her fist. He told the detectives, “Isabella was in a rage like I’ve never seen before”.
Meanwhile, back in the interrogation room with Isabella, she hadn’t budged on her story. Detectives asked her where the cuts on her hands and the scar on her arm had come from. Isabella said that her abusive mother had attacked her with scissors, which was what prompted her to run away in the first place. Investigators pointed out how strange it was that she had the same cuts and scars as Isabella had, that had come from the police dogs when they were searching for her in the parking garage. Isabella just chalked it up to another strange coincidence.
For what seemed like the hundredth time, Isabella asked to be fingerprinted or have her DNA taken so she could prove that her story was true, that she was Samantha Gonzalez. Detectives finally brought someone in to swab her cheek for DNA, but explained to her that the results wouldn’t be ready for several months.
Detectives brought in the bags that had been found with Isabella in the parking garage. Isabella told them that she’d stopped at a market after running away and that a woman there helped her, buying her some underwear and sanitary pads because she looked so dirty and disheveled. She agreed when officers asked if she’d be on the security camera at the market.
In fact, someone from the store, the H Mart, had called detectives to tell them that they had the woman police had been searching for on surveillance video. In the video footage, Isabella was covered in blood and still wearing the pink sports bra and turquoise shorts that Ryan had seen her wearing when she left the bathroom.
Those who’d been in the H Mart that day said that Isabella told them that someone had tried to sexually assault her. The video showed her walking into the H Mart bathroom. Inside the bathroom, detectives found clothing and bandages covered in blood. When the detectives confronted Isabella with this information and asked her why she’d said that she’d been assaulted. She said that the people in the store didn’t need to know about the fight with her mother, that she just needed help.
Now, approximately three hours into the interrogation, Isabella’s calm and flat demeanor had begun to change. Though she continued to stick to her story, Isabella was clearly getting more and more irritated by the investigators and their questions. She started yelling back, shouting at them not to call her Isabella. The detectives, who’d been frustrated with her since the get-go, threatened to bring in Robert, her father, to identify her. Isabella said she didn’t know her father.
Officers brought Robert into the interrogation room. He approached Isabella, who was sitting in a chair, and reached out to gently cradle her face. Isabella pushed away from him and backed into the corner. Detectives asked Robert who the girl was and he affirmed what they already knew, that she was his daughter, Isabella Guzman. Isabella, now agitated, said that she had no idea who that man was, that she wasn’t Isabella. She demanded to be taken to the French Quarter in Aurora so she could see her boyfriend, Gabriel.
As Isabella learned about the crime that she was being accused of, she told detectives how screwed up that this “Isabella” girl must be. Up until the very end of the interrogation, until officers removed her from the room to take her to the hospital to have her hand and arm injuries stitched up, Isabella said that she was Samantha Gonzalez and that she hadn’t murdered anyone. It was difficult to tell, simply from watching her interrogation, if Isabella was a master manipulator and liar, or if she was truly suffering from delusions.
What Happened Next?
Yun-Mi’s autopsy was performed and she was found to have suffered from 31 stab wounds to the face and 48 to the neck; a total of 79 stab wounds. Later reports in court said that Yun-Mi had been stabbed a total of 151 times, including wounds to her torso and abdomen.
Isabella appeared in court in early September to be formally charged with first degree murder and two counts of crime of violence (which is described as “a sentence-enhancing charge”). During the hearing, Isabella made strange faces and gestures at the camera, sometimes smirking at people. This eventually was the reason Isabella became “Tik-Tok famous”, with people becoming weirdly intrigued with the beautiful young girl who’d savagely murdered her mother. There was even a Tik-Tok trend where people would make their own videos, mimicking Isabella’s strange facial expressions in the courtroom.
The judge ordered Isabella to be held without bond at the Arapahoe County Jail. Before her court appearance, Isabella essentially had to be dragged out of her cell because she’d refused to leave.
Her father, Robert, told local news that nobody in their family could understand what would’ve brought Isabella to do this. He said, “Isabella is a good kid, she’s good hearted…but I don’t know what could’ve happened, honestly, to provoke this kind of reaction.”
Isabella’s aunt, Melanie Guzman, said that she’d last visited Isabella a few months ago, and that she seemed like a normal teenager. Melanie said, “Her demeanor is pretty sweet. She’s very coquette. I can see her yelling, screaming, and storming off and locking herself in her room and turning on her Ipod…but not being violent like that.”
In June of 2014, Isabella entered a plea of not-guilty by reason of insanity. Doctor Richard Pounds, who’d evaluated Isabella, testified that she was schizophrenic and had been suffering from significant delusions for quite some time. He said that it was clear that she wasn’t well. “There were obvious signs of hallucinating. She was staring into space, having conversations with people who were not present, and she was laughing at herself.”
Isabella’s attorneys stated that the delusions were what caused Isabella to stab her mother to death. They said that Isabella didn’t believe that Yun-Mi was her mother, but that she was a woman named Cecilia (the woman she’d addressed the email to earlier that day). Isabella believed that the world would end if she didn’t kill Cecilia, so she did.
George Brauchler, the state’s District Attorney said, “We punish people who make decisions to do wrong when they knew better and they could have done something differently. And in this particular case I am convinced, based on the evidence that I’ve seen and the information that’s been presented in court, that this woman did not know right from wrong and she could not have acted differently than she did, given the significant schizophrenia and paranoid delusions, audible, visual hallucinations that she was going through. I was convinced of it and I felt like in the interest of justice I had to take these steps.”
Isabella’s plea was accepted and she was remanded to the state’s mental hospital until she was deemed to no longer be a threat to herself or her community.
In 2020, Isabella, then 25 years old, did a virtual interview with CBS4. She said,
“I was not myself when I did that, and I have since been restored to full health.”
She also commented on the actual murder, saying “The fight with my mom was terrible and I was injured in the process. I have the scars on my hands.”
Isabella told the interviewer that she’d been abused by her family for several years before the murder, saying, “My parents are Jehovah’s witnesses and I left the religion when I was 14, and the abuse at home worsened after I quit.”
Isabella said that she would take it back if she could, but that she was no longer mentally ill and no longer a danger to herself or others.
In June of 2021, Isabella’s request to leave the Colorado Mental Health Institute at Pueblo was denied, however a judge ruled that she will be allowed to leave the hospital for group therapy and other therapy, but is required to wear a GPS tracker.
