An young Idaho woman and her teenage boyfriend have been formally charged in the brutal beating of a 16-year-old girl on a basketball court, months after the incident took place.
Kierstan Leann Morgan, 19, and Jiler Joe-Bryan Hainsworth, 18, were charged with aggravated battery, East Idaho News reports. Hainsworth also faces a misdemeanor assault charge and a witness intimidation charge.
Charging documents say Idaho Falls Police responded to Tautphaus Park at about 10:30 p.m. on May 7, 2025, and ultimately found the 16-year-old victim in a hospital with a blood mouth, loose teeth, swelling to her upper lip, a swollen eye, a large bump above the other eye, and multiple abrasions to her head, face, and arms.
The girl told investigators she was playing basketball with friends when the attack happened. She said that Hainsworth, who was 17 at the time, accused her of flirting with him, and he told his girlfriend to beat her up. At that point, Morgan obeyed the instructions from her underage boyfriend and began yelling threats at the victim, who walked away.
But Morgan didn’t relent and charged up behind her, shoved her to the ground and mounted her, grabbing her hair and slamming her face into the ground. The girl said she thinks she may have passed out because she doesn’t remember much beyond that point.
Witnesses corroborated the girl’s accounting and further said that Hainsworth stopped them from intervening, threatening one bystander if they interfered.
Police viewed video of the assault and described it as a “brutal beating.”
One of the witnesses — the one Hainsworth threatened — eventually rendered aid to the victim and contacted her family members to get her to a hospital.
Police went to speak with Hainsworth — who was still wearing the same clothing he was wearing in the video — but he refused to provide any information and rude to officers, the court documents say. When they later spoke with him on the phone, he yelled profanities at the officer and insisted he didn’t start the fight.
Morgan was charged on May 23, 2025, but police were unable to reach her. A warrant for her arrest was filed, and she was finally taken into custody on June 11. Hainsworth wasn’t charged until January 13, and he was finally arrested on February 2. He has a preliminary hearing scheduled for Friday.
Morgan has a pretrial conference set for March 10.
Both are out on bond.
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[Featured image: Jiler Hainsworth and Kierstan Morgan/Bonneville County Jail]
