CASPER — The Cheyenne 21-year-old charged with shooting a 16-year-old Casper teen initially told a Natrona County Sheriff’s Office investigator that he tripped while playing a game, discharging the gun in a “one-in-a-million fluke kind of thing” that shot the boy in the head.
But the NCSO arrest affidavit tells a different story.
Witnesses, including the fiancée of suspect Sebastian A. K. Belden, told police both Belden and the teen had weapons on the afternoon of May 11 and that Belden frequently took his Taurus G3 9 mm from his waistband and pointed it at the teen’s head.
“During most of those incidents, (his fiancée) told Belden to put the firearm away,” the affidavit states.
Belden eventually confessed May 21 in a follow-up interview with authorities that he pulled the weapon from his waistband, pointed it at the teen, manipulated the safety lever to “make sure nothing bad happened” and agreed with an investigator that the only way it could have gone off was that “his finger was on the trigger.”
Belden appeared in Casper Circuit Court on Tuesday facing two charges of aggravated assault and battery stemming from the Mother’s Day shooting that sent the teen first to Banner Wyoming Medical Center for treatment and then to Children’s Hospital Colorado for extended care.
The affidavit states the teen was found with a gunshot wound to the left side of his forehead above the left eye and an exit wound on the left side of his head above and behind his left ear.
Sheriff’s deputies responded to the scene in the 100 block of South Washington just after 7 p.m. on May 11 after multiple calls to 911 about a male being shot in the head near the corner of East 1st Street and South Washington.
Deputies found a loaded SCCY handgun on the ground within reach of the victim, with a live round in the chamber and a baseball style hat near the teen that had a bullet hole through it.
Loaded Weapon
At the scene, deputies had been told Belden had thrown his firearm into his backyard in the 100 block of S. Washington St. The weapon was loaded and had a live round in the chamber when deputies found it. The safety was on, the affidavit states.
Belden initially told deputies he had a bag of candies in his truck and had gone to get more when he and the victim began to joke around.
They started what he characterized as a game of tag. Belden said he pulled his handgun from his waistband, tripped and the “gun ended up going off.”
Belden said he then went to his apartment to try and get something to help stop the bleeding coming from the teen’s head.
“Through the interview process, Belden explained he was a member of the Wyoming National Guard, and he was previously instructed on the use of firearms from a professional standpoint through his training,” the affidavit states. “It was worth noting that Belden did not carry his handgun in a holster, it was simply concealed in his waistband.”
During interviews with Belden’s girlfriend and forensic interviews with 12-year-old and 14-year-old minor girls who had witnessed the shooting, investigators were told that Belden asked them to lie to law enforcement and tell them he tripped over something and that is what caused his weapon to go off.
All three of the females told investigators that during the day Belden pulled out the 9 mm from his waistband and “pointed it at or put it to (the teen’s) head.”
They also told investigators that there was no animosity between the pair and Belden’s girlfriend told deputies that Belden had bought the SCCY handgun for the 16-year-old.
The Shooting
Belden initially told an investigator during the May 21 interview that his hand and weapon were low near his waist, and he had been starting to orient towards the teen when the weapon fired.
The investigator challenged Belden’s account, saying a hat the teen wore and the entry and exit of the bullet through the hat seemed to indicate that Belden was in a more “traditional shooting position” standing when the gun discharged.
Belden responded that the investigator’s assessment “sounded a little bit more accurate.”
Under questioning, Belden initially denied buying the weapon for the teen. But a search of his cellphone uncovered a contact on Belden’s phone labeled “FBI Agent (Dumb Ass)” determined to be Belden’s reference for the teen victim.
The teen had texted Belden, “Wanna hang out. I might get the rest of the money for the pew pew.” A firearm is commonly referred to as a “pew pew,” the affidavit states.
The investigation found that one of the teen’s family members discovered the teen with the weapon, even though Belden initially told deputies he only allowed him to carry it from time to time.
During a second interview May 21, Belden confirmed he had purchased the weapon for the teen and had received money for it.
He also was asked if they were playing with their weapons earlier May 11 at a Casper car dealership.
“Belden was specifically challenged on whether or not he and TC pointed firearms at each other when they visited a vehicle dealership in Casper,” the affidavit states. “Belden initially said he did not remember if he and (the teen) pointed guns at each other. Belden then said, ‘That could have happened.’”
Investigators found the purchase forms for the weapons on March 28, 2025, and April 16, 2025. The affidavit states that a video at the store where the SCCY handgun was purchased showed Belden’s fiancée and the teen were with him.
An Apology
Belden also wrote an apology letter to the teen’s family and a representative of his delivered the letter to the Casper Police Department asking it to be given to the teen’s family. The letter was given to the Natrona County Sheriff’s Office, the affidavit states.
“The note expressed regret and remorse on behalf of Belden for hurting (the teen),” the affidavit states. “The note also indicated that the shooting was a ‘terrible accident’ and asked for the (teen’s) family’s forgiveness.”
In Casper Circuit Court on Tuesday, Belden was read the two counts of aggravated assault and battery charges he faces. Bond was set at $50,000 cash or surety. A preliminary examination on the charges will be scheduled.
During his appearance Belden informed the court that he had moved to Cheyenne for a new job. He also told the court he was a member of the Wyoming National Guard.
The affidavit states on that May 21, Belden told the NCSO investigator about the potential move and that he would turn himself in if any charges were filed.
“Belden said he was doubtful that law enforcement would file any charges against him,” the affidavit states. He also told the investigator should charges be filed, they “wouldn’t be anything serious.”
Both aggravated assault and battery charges carry a maximum penalty of 10 years in prison and a $10,000 fine.
Dale Killingbeck can be reached at dale@cowboystatedaily.com.
