Executive Summary
- Frederick Stephen Mattinson was sentenced to two consecutive terms of 1-15 years for aggravated assault.
- The victim suffered fractures to nearly every bone in her face during the October 2024 incident at an Ivins resort.
- The judge rejected the defense’s argument for concurrent sentencing based on ketamine-induced delusion.
Frederick Stephen Mattinson, 47, of Washington City, was sentenced to consecutive prison terms on December 11 at the 5th District Court in St. George, Utah, following a brutal assault that left a woman with extensive facial fractures. District Judge Keith C. Barnes handed down the sentence after Mattinson pleaded guilty to two felony counts of aggravated assault stemming from an October 2024 incident at a resort in Ivins.
According to court records, the incident occurred on October 21, 2024, at the Red Mountain Spa. Santa Clara-Ivins Police officers responded to a 911 call placed by Mattinson, who claimed he was under the influence of ketamine and believed he had killed someone. Upon arrival, authorities discovered an unresponsive woman in a pool of blood. Medical reports presented during the proceedings indicated the victim suffered fractures to nearly every bone in her face, including both orbital bones, and a laceration to the back of her head resulting in a brain bleed.
During the sentencing hearing, Prosecutor Jerry Jaeger described the event as a “savage attack” where the victim was “left for dead.” The prosecution noted that the charges had been amended from attempted murder to aggravated assault as part of a plea agreement reached in September. Jaeger emphasized Mattinson’s criminal history and argued that the brutality of the beating warranted severe punishment. The victim and her brother also addressed the court, detailing the traumatic physical and emotional recovery required after the assault.
Defense attorney James Wright advocated for concurrent sentences, arguing that the assault constituted a single criminal episode fueled by a drug-induced delusion. Wright stated that Mattinson and the victim were on a romantic trip and had used ketamine, a substance with which they had little experience. The defense contended that Mattinson was in a “ketamine haze” and did not intend to commit violence, citing a lack of violent criminal history since 2006.
Judge Barnes rejected the defense’s request for concurrent terms, characterizing the incident as “one long brutal beating” that justified treating the actions as distinct episodes. The judge sentenced Mattinson to serve 1 to 15 years in the Utah State Prison for each count, ordering the terms to run consecutively. If Mattinson serves the full sentence, he would not be eligible for parole until 2054.
Judicial Sentencing Factors
The court’s decision to impose consecutive rather than concurrent sentences underscores the judicial discretion exercised in cases involving extreme violence, even when the defense argues for a single criminal episode. By ruling that the prolonged nature of the beating constituted multiple episodes, the court established a high threshold of accountability for drug-induced violence, explicitly rejecting substance abuse as a mitigating defense for the severity of the injuries inflicted. It is important to note that criminal charges are formal accusations, and the presumption of innocence applies to all defendants until guilt is proven in a court of law, a standard met in this instance by the defendant’s guilty plea.
