Witness accounts, location records and the defendant’s later statements helped investigators connect Patrocinio Perez to a 2021 shooting in Magna.
SALT LAKE CITY, Utah — A Snapchat address led Patrocinio Perez to a crowded Magna house party in August 2021, investigators said. In the days and weeks afterward, Snapchat location information, ride-service records, telephone data, reports from people who heard him claim responsibility and Perez’s own statements helped authorities retrace that trip and build the double-murder case that has now resulted in a minimum 45-year prison sentence.
The digital evidence gave investigators a way to reconstruct movement around a crime scene where dozens of teenagers and young adults had been present and many fled as police arrived. Authorities said Perez had received the house address from a girl through Snapchat before getting a ride to the party. Call records, Uber information and Snapchat location data later placed him in the area shortly before and after Juan Valentine Rodriguez, 19, and Ivan Valenzuela, 18, were shot. Perez eventually told police that he entered the home, shot both men and left, according to the charging account.
That admission came after investigators had already begun focusing on him through another form of evidence: what other people said Perez had been telling them. Police received reports that he claimed he was responsible for the shootings, including statements made to people investigators identified as gang members. Prosecutors later pointed to social-media posts in which Perez discussed weapons and ammunition. At his 2026 sentencing, Deputy Salt Lake County attorney Vincent Meister said Perez had boasted about “upgrading his belt” and referred to having “ultra lethal” ammunition. Those comments became part of the state’s account of his conduct after the killings.
The crime the evidence was helping police reconstruct occurred Aug. 15, 2021. Officers responding to a house party in Magna encountered a large group leaving the area. Inside they found Rodriguez and Valenzuela with gunshot wounds. Rodriguez was pronounced dead at the scene. Valenzuela was taken to a hospital but died shortly afterward. A 17-year-old girl, later publicly identified as Autumn Baker, had also been shot in the arm. Charging documents said police estimated that 30 to 50 teenagers and young adults were at the gathering, making the house both a crime scene and the setting of a mass traumatic event for those who escaped physical injury.
Investigators later said Perez offered a strikingly limited explanation for attacking two people he did not know. According to charging documents, he told police that he believed Rodriguez and Valenzuela were speaking negatively about his friends. Prosecutors said he had also mentioned seeing a haircut he associated with a rival gang, while asserting that neither victim actually had the haircut Perez described. At sentencing, Meister said the evidence did not support self-defense. Instead, the prosecutor said Perez approached the men without warning and deliberately moved close enough to attack before they realized what was happening.
The state’s courtroom description added detail that was not necessary to establish the broad sequence of the crime but became important when the judge considered punishment. Meister said Perez moved up the stairs in a way meant to keep him from being detected, then fired at Rodriguez at close range before shooting Valenzuela moments later. A bullet fired during the attack also struck Baker. Prosecutors described the violence as an ambush and emphasized that the victims had little or no warning. The sentencing presentation therefore connected the investigative evidence of Perez’s presence with a prosecution account of how he acted once inside the house.
Over time, the evidence developed into charges that exposed Perez to severe penalties. He was charged with two counts of aggravated murder and firearm offenses, along with possession of a weapon by a restricted person and obstruction of justice. The litigation stretched across years while Perez faced additional cases. In 2023, prosecutors amended the murder allegations so they could be treated as capital offenses and filed notice of an intent to seek the death penalty if Perez were convicted. By 2026, however, the murder case ended not with a jury verdict but with a negotiated guilty plea.
Under that agreement, Perez admitted two aggravated murders and three first-degree felony counts involving discharge of a firearm. Prosecutors agreed to recommend 15 years to life on each murder conviction rather than 25 years to life. Charges including obstruction and possession of a dangerous weapon by a restricted person were dismissed, and other pending cases were addressed as part of the broader resolution. The agreement narrowed the sentencing range but did not eliminate a critical decision for Third District Judge Heather Brereton: whether the five prison terms would run at the same time or one after another.
By the time Brereton made that decision Aug. 24, 2026, the digital trail and charging evidence were no longer being used to prove guilt at a trial. Perez had already pleaded guilty. Instead, the hearing concentrated on punishment and harm. Meister asked for consecutive sentences and told the judge that two young men had been killed, Baker had been wounded and dozens of partygoers had been forced to witness or respond to the violence. The prosecutor also raised Perez’s reported posts and his involvement in other alleged shootings as part of the history he wanted the judge to consider.
The court also heard what cannot be measured through location data or call records. Baker described in a written statement how her life had changed since being shot at 17. She said she developed post-traumatic stress and struggled with sleep and loud noises. Valenzuela’s sister described a family that still felt incomplete five years after his death. She asked that he be remembered as a brother, son, cousin and friend rather than simply as a person killed in gun violence. Their accounts gave the hearing a different evidentiary focus: not who had committed the crime, but what the crime had continued to mean.
Perez’s lawyer, Rudy Bautista, told the judge his client had changed his view of the life he had been living and accepted responsibility. Perez addressed the victims’ families with an apology. Brereton nevertheless said the plea agreement was notably favorable to him, calling it a “gift.” She cited the two deaths, Baker’s injury and the danger imposed on everyone at the party. The judge imposed 15 years to life for each aggravated murder and five years to life for each of the three firearm counts, then ordered every term to run consecutively.
The result was a minimum far longer than either murder sentence viewed by itself. The two murder terms total at least 30 years. The three firearm terms add another 15 years. Perez therefore faces a minimum of 45 years in prison, with the possibility that the life-range sentences could keep him confined longer. A sentence from another case was ordered to run concurrently and does not add to the 45-year minimum. An initial report from the sentencing briefly understated the minimum before being corrected to include all three firearm terms.
The investigation illustrates how several kinds of evidence can converge without any single source carrying the whole case. Witnesses helped direct investigators toward Perez. Snapchat information helped establish how he learned of the party and where his account was located. Ride and telephone records helped trace his movement. His later statements supplied an admission and an asserted reason. Social-media activity supplied additional evidence prosecutors used to characterize his conduct afterward. Together, those sources allowed police to move from a chaotic party scene to a named suspect and ultimately to guilty pleas.
The records also preserved the limits of what investigators could claim. The evidence supported that Perez believed the victims had spoken negatively about his friends; it did not establish that Rodriguez or Valenzuela had actually done so. Prosecutors said the claimed gang-associated haircut was not present on either man. Those distinctions mattered because the state’s final account did not portray a documented dispute between the men. It portrayed a deadly attack based on Perez’s own perception of people he did not know.
Five years after the first location records and witness accounts began pointing toward Perez, Brereton’s sentencing order moved the case into its final criminal-justice stage. The same digital trail that once helped investigators establish who had arrived at the Magna home is now part of the closed evidentiary history of two murder convictions. Perez has been ordered to serve at least 45 years, while the families of Rodriguez and Valenzuela and the surviving victim continue to live with consequences that, as the sentencing hearing showed, did not end when the investigation did.
Author note: Last updated September 30, 2026.