Police Say They Know Who Killed Alicia Tverberg. Six Years Later, the Suspect Is Still Free.

Years after her childhood best friend was murdered, Selina Maestas sat outside the suspected killer's home. Maestas watched silently as Mario Raymond Sanchez walked in and out of the small, tan brick house on a residential street in Commerce City, observing from afar as he continued living his life...while her friend's life had ended.

Even now, investigators accuse Sanchez of murdering Alicia Marie Tverberg. He was arrested in connection with the crime in January 2020, a month after the 21-year-old woman was found fatally shot inside a stranger's Adams County apartment the day after Christmas 2019. But Sanchez was never charged with Tverberg's death, nor were any other suspects.

Almost six years later, Tverberg's case has gone cold.

"To this day, I have not been able to rest. I really thought we had him," Maestas says. "I've considered going up [to Sanchez's home] and risking my life to get a confession out of him. I just never did."

The 17th Judicial District Attorney’s Office declined to file charges against Sanchez a week after his arrest, pending further investigation. But the case's co-lead detective, Adams County Sergeant Andrew Martinez, says the investigation was exhausted long ago, and he claims it led them directly to Sanchez.

The discovery of the murder weapon, fingerprints at the crime scene and digital data like social media activity and cell phone pings all implicate Sanchez in the murder, according to an arrest affidavit for Sanchez from 2020. But because multiple people were present when Tverberg was killed, and none of them identified the shooter, Martinez says prosecutors feared they couldn't prove beyond a reasonable doubt that it was Sanchez who pulled the trigger.

"I was confident going in that we had the person, and I'm still confident that we had the person in custody," Martinez says. "With the case that we had, I would have liked to have seen it go to trial. ...I feel that it would've been better to go to trial and have a jury decide whether the evidence was sufficient."

The DA's office rejected interview requests from Westword, citing concerns that discussing the case could jeopardize a future prosecution. But the possibility of a future prosecution seems slim.

Spokesperson Chris Hopper says that in 2020, the DA's office assigned an internal investigator to the case who remains "committed to following any new evidence that warrants further review." According to Martinez, the case was reviewed multiple times by different detectives with the Adams County Sheriff's Office, most recently in early 2024, but they yielded no new paths forward.

For Tverberg's loved ones, hope for justice is dwindling. Her mother, Irene Gonzales, says she had regular meetings with the DA's office for three years, but there was never any progress to report. She has pushed investigators, collected her own evidence and offered a $10,000 reward for information about her daughter's murder. Nothing has worked.

"They had told me they know who did this and it's a marathon, not a sprint," Gonzales says of the DA's office. "But here we are, five years later, and nothing's happened. That's a hell of a marathon."

One Body, Three Suspects

After spending a month in jail, an Adams County man returned home on the evening of December 26, 2019, to find his front door ajar. Though he lived alone and had been gone for weeks, his apartment on Galen Court was now in disarray, littered with beer bottles, used cigarettes and trash.

The party house transformed into a grisly crime scene when he entered his bedroom.

Lying on the ground beside his bed was the body of an unknown young woman. She had been dead for at least one week, according to the autopsy report, shot in the abdomen with a single round of nine-millimeter ammunition. The manner of death was homicide.

The Jane Doe was later identified as Tverberg, a 21-year-old resident of Henderson whose family had been looking for her for days.

Tverberg was living with her mother at the time of her death, searching for a new apartment and working at a local convenience store. She'd left home on December 9 for an extended celebration of her 21st birthday, which was on December 16; Gonzales kept up with her daughter via social media messages. The replies stopped coming after December 17. Shortly after the discovery of the body, police arrived on her doorstep.

"The police said they wanted to inform me that they found my daughter deceased," Gonzales recalls, crying. "She is my only child. She is my best friend. She is all I want. I would lose my life for her in a second."

The man reported Tverberg's death to 911, later telling investigators that he had given someone permission to stay at his apartment while he was in jail: a fellow inmate's girlfriend named Lindsay Jenson, according to a search warrant from January 2020. Fingerprints lifted from beer bottles in the apartment identified two other people allegedly present at the crime scene: David Vargas and Sanchez, according to his arrest affidavit.

Detective Martinez claims that Sanchez, Vargas and Jenson were the only people inside the apartment when Tverberg was shot in the early hours of December 18 — and only one of them could have pulled the trigger — citing physical evidence, digital data and witness interviews.

None of the suspects nor their attorneys responded to inquiries from Westword.
Tverberg was familiar with the three suspects through her boyfriend at the time, Adalberto "Beto" Chavez. During an interrogation, Chavez reportedly told detectives that he brought Tverberg to the Adams County apartment so that she could speak to the three because they were upset with her.

According to Martinez, Chavez claimed that a few days before her murder, Tverberg took him, Vargas and Jenson to a drug dealer and the dealer tried to rob the group. Vargas and Jenson accused Tverberg and Chavez of setting them up, which they denied. Chavez said that he brought Tverberg to the apartment, left to pick up weed, and returned as everyone was running away, yelling that cops were coming. Martinez says Chavez's digital footprint and other interviews corroborate his movements.

"Her boyfriend [says he] brought her over so they could scare her," Martinez says. "If he knew what they were going to do, if he knew to what extent, we don't know."

On December 16, 2019 — the day of Tverberg's 21st birthday and ten days before her body was found — Tverberg told multiple people that she had been jumped and robbed, according to the search warrant. The warrant notes that Chavez suffered a gunshot wound to his arm during an altercation in Denver that same day.

This incident appears to align with the timing of the reported drug deal-turned-robbery, though Gonzales describes the circumstances very differently in speaking with Westword. She claims Tverberg, Chavez and Vargas were at a party in Denver when Chavez assaulted Tverberg, who then called a friend for help. The friend allegedly showed up with a carload of people and a conflict ensued, culminating in a shootout and in Tverberg being jumped.

Tverberg's friends and family describe Chavez as extremely physically abusive. Gonzales claims he beat her daughter on numerous occasions and isolated her from her loved ones. She speculates that Chavez would have allowed Tverberg to take the fall if he got into trouble.

"I still believe she lost her life because of her boyfriend," Gonzales says. "I believe that he'd do anything to save his own ass from what was about to come down on him. And I believe my daughter was blamed and used as a pawn and murdered for no reason."

Three months after Tverberg's death, Chavez was arrested in connection to a different murder: the fatal shooting of 17-year-old Jeremiah Baca in Denver in January 2020. Chavez is currently serving a 22-year prison sentence for the crime.

While it is possible that Chavez orchestrated the circumstances leading to Tverberg's murder, or had knowledge of it, Detective Martinez maintains that the only plausible gunman is Sanchez, Jenson or Vargas.

"We were able to positively identify the four people, and Alicia was one of them, who were in the apartment at the time of the incident," Martinez says, adding that physical evidence indicates Tverberg was killed in the same spot her body was found. "I am fairly confident that there was an argument in the apartment, and I am confident that Mario, Lindsay and David were a part of that," he asserts.

"And I am confident that Mario Sanchez is the one who murdered Alicia."

The Case Against Sanchez

Authorities arrived at the Commerce City home of Sanchez's mother on January 23, 2020, wanting to discuss why they had found his fingerprints at the scene of a murder.

Sanchez agreed to go to the station for questioning, while officers remained at the house awaiting a search warrant. Hours later, a family member arrived to retrieve a dog from the home; an officer escorted the woman as she searched for a leash inside a child's bedroom, where Sanchez had slept the night before. But when she opened a dresser drawer, rather than a leash, the officer saw a nine-millimeter handgun inside.

Ballistics determined that the handgun was the weapon used to kill Tverberg, according to Sanchez's arrest affidavit. Sanchez's DNA was also later found on the gun.

When interrogated, Sanchez admitted to possessing the firearm, claiming he'd "found it" in an alley a month prior; Sanchez is a convicted felon who is not legally allowed to own firearms, the affidavit notes. Sanchez is a self-admitted member of the Bloods street gang with a lengthy criminal history, which at the time included four felony convictions and one misdemeanor assault involving domestic violence, according to the affidavit.

Sanchez reportedly acknowledged his presence in the apartment during the fatal shooting of Tverberg — though he described her death as an accident, telling detectives that the gun fell out of his backpack and "just went off." He claimed he didn't "even know how the fuck this shit happened," the affidavit notes.

That allegation does not align with physical evidence. The autopsy report found that Tverberg's bullet wound had a downward trajectory, meaning the gunshot came from above the height of her abdomen. If the firearm fell onto the floor and fired on its own, the wound path would be upward.
The search warrant for Sanchez's mother's home details social media interactions between Sanchez and Jenson that could suggest involvement in the crime.

Two weeks before the murder, Sanchez messaged Jenson on Facebook asking for nine-millimeter bullets, after Jenson asked Sanchez about the price of "a ball of blk," presumably referring to heroin, the warrant reads. In the hours and days after the murder, Jenson called and messaged Sanchez repeatedly to no response, in addition to sending other people frantic messages, including "it's a 911 and we need to find Mario asap," and telling someone not to go to "the apartment" "like ever...we were never there."

Detective Martinez says investigators tried to question Jenson and Vargas, but both refused to talk. He believes the only thing that will lead to a prosecution is if one of the three suspects confesses, or points the finger at one of the others.

"We have the gun, we have the digital data, we have the interviews as far as they can take us," Martinez says. "We've sat at the table thinking, 'What could we get?' The only thing that we haven't gotten is an admission from Mario or one of the witnesses saying they positively saw him pull the trigger. At this point, unfortunately, that's what I think it would take."

The DA's office appears to have reached the same conclusion. In mid-2024, an investigator told Tverberg's mother that they "dream" someone will come forward with a confession in the case "because I’m sure that’s what it’ll take," according to an email exchange reviewed by Westword.

"I can’t understand why they would sweep this under the rug. It’s a murder case and you know who did it," Gonzales says. "This is felony murder. I want everybody charged, everyone who was involved in this."

Bringing charges against all three suspects for allegedly participating in or concealing the murder would be a decision for the DA's office, Martinez says.

"I am frustrated that we aren't going forward with charges," Martinez adds. "But I do understand where they're coming from and what they're saying. We'd be leaving it in the hands of a jury to say he's guilty or not guilty. ...It gets frustrating when you get to that end, where the only thing [you need] is somebody talking, and nobody is talking."

According to Martinez, none of the three suspects or Chavez have agreed to speak to investigators again since 2020. The last time officers contacted Jenson, she was on the streets in the Denver metro area, he says. Vargas is currently serving a 26-year federal prison sentence for committing armed robbery in November 2020. With Vargas and Chavez behind bars, speaking to law enforcement carries a stigma with fellow inmates, Martinez points out.

"Essentially, they have nothing to benefit," explains Sergeant Adam Sherman, public information officer with the Adams County Sheriff’s Office. "If something were to happen, it would have to be generated by them, because our facts and our evidence aren't really going to change."

Though he was not charged with Tverberg's murder, Sanchez was convicted of firearm possession by a prohibited person for having the murder weapon. He was sentenced to 37 months in prison and released on parole in September 2022.

During the federal court case for the firearm charge, the murder was discussed at length. Prosecutors sought a sentence enhancement based on the allegation that Sanchez caused Tverberg's death via involuntary manslaughter, according to a transcript of Sanchez's sentencing hearing in September 2021. United States District Judge R. Brooke Jackson denied the enhancement, noting that Sanchez had not been convicted or even charged with the death.

"It is absolutely clear to me, based on my knowledge of the case and the extensive motion hearing that we had, that Mr. Sanchez had some involvement in the circumstances surrounding the death of Ms. Tverberg," Jackson said during the hearing. "[But] I value very greatly the presumption of innocence that the gentleman enjoys.

"If he committed the homicide and gets away with it, I'll be very sorry that that is the result."

'Not a Single Clean Person'

Before she was gunned down in a stranger's apartment, Tverberg dreamed of a better life. She filled pages of a composition notebook with positive affirmations and plans for the future. She wanted to set boundaries with friends she viewed as negative influences; dedicate more energy to work, music and writing; and "quit the things that changed me."

"CHANGE YOUR LIFE OR YOU WON'T HAVE ONE," Tverberg wrote in all caps at the bottom of one page, next to a small doodle of a heart.

Gonzales found the notebook among her daughter's things following her murder. In between pages detailing Tverberg's aspirations and self-help strategies, a different person's handwriting crept into the notebook in mid-2018. Messy scribbles in blue pen tracked dollars owed and paid for drugs, using slang terms like "clear" (code for methamphetamine) and "ball" (code for cocaine). Gonzales claims the writing is that of Chavez, Tverberg's boyfriend.

"He was very abusive, he was an addict, he was [gang] affiliated," Maestas says of Chavez. "Knowing [Tverberg], she kind of looks past the bad things, and she tries to let the good outweigh the bad. She overlooks all of the negatives in a person and will always see the beauty in someone."

Her daughter had gone through phases of drug use but was always able to seek treatment and get clean, Gonzales says, adding that Tverberg was not part of a gang. She speculates that Tverberg may have gotten caught in the middle of dangerous people during her relationship with Chavez.
Gonzales spent years meeting with investigators, attending Sanchez's court hearings, and speaking to anyone who might have information about what happened to her daughter. But after nearly six years without justice, she now suggests that misconduct by authorities may be responsible for the lack of progress in the case.

While the DA's office refuses to discuss the case for fear of harming a potential future prosecution, details of the investigation were made public record years ago as part of Sanchez's federal gun possession case, including the arrest affidavit, search warrant and autopsy report. Gonzales says the documents have spread online among those who knew Tverberg.

Gonzales points to individuals involved in the case who were later exposed for wrongdoing in unrelated matters:

• Dan Danielson, one of the DA's office's investigators who worked on the case, resigned in 2023 after he was arrested in an undercover prostitution sting.
• Former Adams County Sheriff Rick Reigenborn, who held the position at the time of Tverberg's murder until 2023, was convicted of forgery and official misconduct for falsifying records for state-mandated law enforcement training that he did not complete, a scheme that also involved the office's undersheriff and division chief. This year, Reigenborn was also found to have wrongfully fired top commanders as political retaliation.
• Judge Jackson from Sanchez's federal gun case was found to have violated federal law in 2021 for failing to recuse himself in dozens of cases that involved companies in which he had financial stakes.

"In my daughter's investigation, there is not a single clean person," Gonzales says. "I think they literally fucked up everything."

In her dealings with the DA's office and the sheriff's office, she says there seems to be conflict and tension, with each side insinuating blame for the stalls on the other. Gonzales has also butted heads with investigators. She expresses frustration over mistakes such as the search warrant incorrectly reporting that she hadn't seen her daughter since May 2019, and authorities allegedly not following up on leads she provided regarding people with information about Tverberg's movements leading up to the murder.

Detective Martinez denies any conflict with the DA's office, describing the situation as a professional disagreement and reiterating that he understands the perspective of the DA's office.

"There's a difference between feeling that this is what happened, as opposed to proving a case beyond a reasonable doubt to a jury," Sergeant Sherman adds. "The burden of proof, the standards are super high on their end."

"I don't want Irene or anyone to think that I didn't give [the investigation] my all and my 100 percent attention," Martinez says. "Did I give it my everything? I know that I did. I just wish that it was a different outcome. ...I wish that I could bring her a guilty verdict and show her who killed her daughter and bring Alicia justice."

Martinez says investigators continued interviewing individuals regarding the murder, but if they were not in the room when it happened, their testimonies are largely hearsay, which officials cannot build a prosecution on.

That is a hard pill to swallow for Tverberg's loved ones. They have spent the last five-plus years listening to different stories from people claiming to know what happened that fateful night, and hearing whispers from friends-of-friends who allege that the suspects brag about getting away with murder.

"We almost had it. We almost had it," Maestas laments. "That man got away with it."

A Life Lost

Christmas and birthday gifts for Tverberg sit inside of Gonzales's home to this day, wrapped and waiting for her to finally return home to open them.

Gonzales says she and her daughter both nearly died when she was pregnant due to a severe case of HELLP syndrome. Tverberg spent over a week in the neonatal intensive care unit after she was born prematurely, weighing just four pounds and measuring sixteen inches long.

"When she came home, I was overbearing. I didn't want people touching her, didn't want people around her," Gonzales says. "I wish I never would have let anybody around my baby."

She describes her daughter as brilliant, thoughtful and gifted in singing and playing the drums. Above all, Gonzales says Tverberg was endlessly loving, recalling how at the age of ten, she negotiated with a store manager to buy her mom a necklace for Valentine's Day with her own money. Gonzales was equally dedicated to her daughter; going to college so she could provide Tverberg with a better life, getting a house so Tverberg could have a backyard, changing her job to work from home full-time when Tverberg struggled with depression.

"Everything that I ever did in my life was for that little girl," Gonzales says through tears. "Now, I don't do anything. I can't look at things because if I see something beautiful, I know she's not here to see it. I don't want to have fun because she can't. I just want to be with her. I don't want to be here without her."

Maestas and Tverberg met in middle school. She calls her friend funny, smart and someone who "could do anything." They were inseparable throughout their youth, she says, referring to each other as sisters and often spending days just sitting in silence together. Though they grew apart into adulthood, they always kept in touch online.

The inbox of Tverberg's Instagram account is filled with unopened messages from Maestas. Even after her friend's death, Maestas says she continued writing to Tverberg about how her day was and what was going on in her life, knowing that the messages would never be read. Maestas still finds herself crying over the loss of her friend several times a week, when she hears a certain song or sees a certain food that Tverberg loved.

"She took a huge part of my heart with her. I haven't been the same the last six years," Maestas says. "It's changed my life completely. The grief hasn't gone away for me, I don't think it ever will. We were supposed to be each other's bridesmaids. I won't get to see her get married or have kids or do all the things that she wanted to do. And I hate that."

Detective Martinez says he tries to remain optimistic that the case will one day reach a resolution. Perhaps one of the suspects will come forward, or perhaps someone hiding important information or evidence will reach out now that some of the individuals involved in the case are behind bars.

"Being a detective, there are cases that linger and stay with you. This is definitely one," Martinez says.

"Even if it's been six years, she's still important," Maestas adds. "She still matters."

Authorities ask anyone who knows anything about Alicia Tverberg's murder to contact Metro Denver Crime Stoppers online or by calling 720-913-7867. Tipsters can remain anonymous and are eligible for a cash reward for information leading to an arrest.