Editor’s note: This story is about an alleged sexual assault case. If you or anyone else needs assistance with sexual assault resources, please call either the National Domestic Violence Center 24/7 hotline at 1-800-799-7233 or the National Sexual Assault 24/7 hotline at 1-800-6564673.
A judge ruled there is enough evidence for felony charges to proceed against one of three men accused of sexually assaulting a 17-year-old girl inside the home of the now-former Ouray police chief last year.
The case will proceed in court, but it’s unclear whether it will move forward through the juvenile court system or as a criminal adult case, pending a judge’s ruling on that question.
Three days of hearings for 19-year-old Nate Dieffenderffer held Sept. 18-20 started with a preliminary hearing on whether he should stand trial on a felony charge of sexual assault. Then the prosecutor and Dieffenderffer’s attorneys presented arguments over whether the case should be moved to juvenile court, as he was 11 days short of turning 18 when the crime allegedly occurred.
The preliminary hearing
After a full day of preliminary hearing testimony from three law enforcement officers on Sept. 18, Seventh Judicial Chief District Judge Cory Jackson concluded that Dieffenderffer should stand trial on a felony charge of sexual assault. The judge cited certain pieces of evidence presented in the hearing, including Dieffenderffer’s admission in text messages to having sex with the woman.
Jackson also said he believes there is evidence that the woman was drugged and that other men aided and abetted Dieffenderffer in committing the sexual assault.
A preliminary hearing is used to determine whether there is probable cause to believe that the person charged with a crime committed that crime. By law, a judge must view the evidence presented at that hearing in a light most favorable to the prosecution.
“It’s important to remember and reiterate: This is not a phase of this proceeding to resolve the evidence,” Jackson told attorneys. “Conflicting statements and conflicting evidence at a preliminary hearing has to be resolved in favor of the prosecution. I can’t engage in credibility findings at this stage.”
Authorities allege the assault occurred at the home of then-Police Chief Jeff Wood in May 2023. Three men were arrested in December: Dieffenderffer, Wood’s stepson who was 17 at the time and has been charged as an adult; 21-year-old Gabriel Trujillo and 19-yearold Ashton Whittington.
Attorneys offered conflicting portrayals of the now-19-year-old woman who said she was assaulted.
Deputy District Attorney Ryan Hess contended someone spiked the woman’s drink with an unknown substance before she was held down and sexually assaulted by Dieffenderffer and Trujillo — a series of events he said the three suspects planned.
Defense attorney Cindy Hyatt attacked the woman’s credibility, noting instances in which the physical evidence didn’t support the woman’s accounts of what happened that night. She also said tests conducted during the sexual assault exam at the hospital didn’t show evidence the woman was drugged, and an empty alcohol container retrieved from the home’s trash also didn’t test positive for date-rape drugs.
Ouray County sheriff ’s investigator Bernie Chism, who first received the report, testified the woman initially didn’t want to report the incident to law enforcement. Her friends convinced her to go to the hospital and the incident was reported by hospital staff, who were required to do so since she was younger than 18 at the time.
Colorado Bureau of Investigation Agent John Zamora, the lead investigator in the case, testified the woman initially did not provide the names of the men she said assaulted her. She described one of the suspects as the son of someone in law enforcement who had a lot of power.
The woman later provided a written statement to CBI with more details, saying she was starting to recall more about that night.
The woman said she had gone to celebrate with Dieffenderffer, who was on leave from the U.S. Army, and Whittington for his 18th birthday but didn’t know Trujillo would be there. Zamora testified that the woman said after drinking one alcoholic seltzer provided to her by Whittington she felt like she had been drugged. She said she felt foggy and woozy, describing how it felt similar to a previous experience she had with anesthesia.
Zamora said the woman told law enforcement she was sexually assaulted on a bed and in the bathroom before she was conscious enough to flee from the home.
Unable to locate her own clothes, she said she put on a sweatshirt that belonged to Wood.
Prosecutors presented a key piece of evidence during the hearing – a voice recording the woman sent to her friend while sitting in the driveway. The woman is sobbing in the recording, saying she’s not sure what happened, she doesn’t know what to do and she doesn’t want to drive home drunk but doesn’t have a choice.
“I think something bad happened. I’m not really sure,” she said in the recording. “I literally had one drink and I’m so f—up.”
Nearly a month later, the woman and Dieffenderffer exchanged messages over an instant messaging app about the night of the alleged assault while a CBI agent was present with the woman. She claimed she was raped and was unconscious for most of what happened. Dieffenderffer apologized.
“Well Jesus when u put it (that) way … I’m sorry there’s really nothing to say to that to justify it. I feel like a s—bag I’m sorry,” he wrote.
Hyatt, though, pointed out instances in which evidence didn’t match the woman’s accounts of what happened that night.
Under cross-examination, Zamora testified the woman claimed to him in a July interview that she was “choked to the point that she almost thought she was going to die.”
“I legitimately thought my life was going to end right there on the bathroom floor,” Zamora quoted the woman as saying.
An examination conducted by a sexual assault nurse examiner, however, found no marks around her neck, Zamora testified.
During her questioning of Zamora, Hyatt also noted that DNA tests found Trujillo’s DNA in several places on the woman’s body but excluded Dieffenderffer and Whittington in almost all cases. Zamora testified the only places where DNA was found that likely belonged to Dieffenderffer was on the woman’s shoulder and in scratches on her back.
During closing arguments, Hess recounted the woman’s description of the alleged assault — that she was assaulted by two men she identified as Dieffenderffer and Trujllo, and that the assault occurred after she felt like she had been drugged.
“These three individuals worked in concert to complete what was going on,” Hess said.
The prosecutor also noted that the woman’s clothes were never found, and that the bottle of alcohol that tested negative for drugs was the only one found by law enforcement. He suggested someone disposed of the clothes and remaining alcohol containers.
Hyatt argued that prosecutors overcharged Dieffenderffer, charging him with a more serious class 2 felony while charging Trujillo and Whittington with lesser class 3 felonies. She contended they did so in order to be able to charge Dieffenderffer as an adult, though he was 17 at the time of the alleged crime.
“The fact that they would wish the person under 18 to face the most serious criminal liability — that would be an odd motive for the prosecution,” Hyatt said.
She said Dieffenderffer would face much harsher punishment if he’s convicted as an adult of a class 2 felony, something she called “hugely disparate treatment.”
Hyatt argued there’s no physical evidence that Dieffenderffer had sexual contact with the woman and “not a single shred of evidence” that she was drugged. She said Dieffenderffer’s DNA was only found on the woman’s shoulder and back, and that Hess’ argument seems to be that because DNA was found in those places, there was a sex assault.
“I don’t know how we make that leap,” she said. The cases against the other two suspects, Trujillo and Whittington, are on hold while the Colorado Supreme Court decides whether prosecutors should be barred from introducing key evidence in Whittington’s case.
Seventh Judicial District County Court Judge Sean Murphy ruled in March that prosecutors couldn’t use several pieces of evidence because they failed to turn it over to Whittington’s attorneys by a deadline outlined in state law. Whittington’s lawyers asked Murphy to dismiss the case or issue sanctions. Trujillo’s attorney filed a similar motion in April for the same reasons cited by Whittington’s attorneys.
It’s not clear when the state Supreme Court will make a decision on the evidence issue.
Arguments over whether to move case to juvenile court
In subsequent hearings Sept. 19 and 20, the defense presented extensive testimony on Dieffenderffer’s childhood experiences and family, in what experts call a “social history.”
Hyatt called a series of experts to talk about their evaluations of Dieffenderffer’s background and research related to his development.
Hyatt painted a picture of a child born into an unstable environment, with his parents in a tumultuous, abusive relationship and near-constant relocation. She also presented testimony about Dieffenderffer’s biological father abandoning him and having substance-abuse issues. She said he was diagnosed with ADHD when he was only 5 years old, had difficulty controlling impulsive behavior, struggled with academics and developed his own addictions and risk-taking behavior by the time he was in middle school.
Hyatt drew on this social history to talk with a clinical psychologist about how these situations affected his development and maturity, and how the instability can cause problems with judgment, decision making and impulse control.
While Hyatt presented evidence that Dieffenderffer’s life stabilized after his mother, Amy, met Wood around the time he was in kindergarten, he continued to struggle with behavior and school. By the time he was in eighth grade, he had failed and had to repeat a year of school. After he started attending a charter school in Maryland for his second year in eighth grade, the family relocated to Ouray for Wood’s new job as police chief. Dieffenderffer started over as a freshman at Ouray School before transferring to an online charter school, from which he graduated.
During his sophomore year, Dieffenderffer started smoking marijuana, and drank alcohol sometimes every weekend, according to social worker Jamie Requa, who prepared the report for the defense. He continued to struggle with behavior and would get grounded by his mom and stepdad, Wood, or have to do physical activity for punishment.
“Amy (Wood) reported they would put a GPS collar on him to make sure he was running laps,” Requa said. Dieffenderffer shook his head and laughed at this detail.
Hyatt also presented testimony from witnesses who talked about the difference between how offenders are treated in juvenile corrections compared to the adult prison system in Colorado, and emphasized the amount of individualized treatment Dieffenderffer might receive if he were convicted and sentenced to the Division of Youth Services. She argued the structured environment and therapy was a better fit for him than what is available in adult corrections.
Hess, the prosecutor, focused his cross examination on details about timelines for juvenile offenders in the corrections system, specifically asking what happens in situations where the offenders reach age 21 before they complete their sentences.
Because the juvenile corrections system loses jurisdiction over offenders when they turn 21, there’s a hearing at age 20 ½ where evidence and recommendations are presented to a judge. That judge can either transfer the offender to the adult prison system to finish a sentence, transfer them to supervision under adult parole, sentence them to community corrections or vacate the remainder of the sentence.
Since Dieffenderffer is now 19 years old, there’s not much time for the case to be resolved and have a potential conviction handled with a sentence in the juvenile corrections system, Hess argued.
“We’re looking at a very tight window between the age as it stands today and 21 years of age,” he said, adding there is a “high potential” that Dieffenderffer would face sentencing after age 20 ½. He also cited testimony from experts who said it could take 18 to 24 months for offense-specific treatment in the juvenile system to produce successful outcomes.
“We’re going to time out, and then what happens?” he said.
Hess also asked the judge to consider Dieffenderffer’s enlistment in the military when considering his maturity level, and to also consider how he has handled Army life.
“Once a child enters active duty, the child shall be considered emancipated,” he said, noting Dieffenderffer was on leave from active duty when the crime allegedly occurred.
Hess also presented evidence of Dieffenderff er’s continued issues with the legal system since he was arrested in this case. Those included an arrest in June 2024, for alleged underage alcohol possession by the Riley County Police Department in Kansas, where he’s stationed at Fort Riley.
In August, Hess said Dieffenderffer was arrested by military police for an incident involving his then-wife, who is also serving in the Army, involving alleged alcohol use and domestic violence. Dieffenderffer became upset during this portion of the hearing, and started crying. They were married in November 2023.
Hess also brought up three instances where Dieffenderffer tested positive earlier this year for marijuana and cocaine, in mandatory testing by the U.S. Army, records obtained through military legal counsel. There was also another incident in January 2024 involving alleged drunk and disorderly conduct. In April, he was arrested for suspected reckless driving and speeding after the Colorado State Patrol pulled him over for driving 126 miles per hour on U.S. Highway 50 in Montrose.
“Here is someone who has been in a highly structured environment and has shown the inability to be (successful) in that highly structured environment,” Hess said.
Judge Jackson is tasked with weighing several factors in making a decision of whether to allow the case to proceed in adult criminal court or move it to juvenile court. Those factors include weighing the seriousness of the offense and protection of the community, the manner in which the crime was allegedly committed and the age and maturity of the defendant.
Jackson said he would issue a written order for the hearing. It’s not clear exactly when that will happen.
