His lawyer insists the two — then aged 18 and 16 — were in a consensual relationship.
Lance Armstrong's son has been charged with the sexual assault of a minor.
The arrest on Tuesday stems from an alleged incident that occurred three years ago, when Luke Armstrong was 18 and the victim 16.
According to the arrest affidavit obtained by KVUE, the now 19-year-old woman reported the incident on November 17, 2020, claiming the assault happened in June of 2018.
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View StoryShe claimed she had gone to a party and had gotten drunk, and called Armstrong to pick her up, to which he agreed.
She said she couldn't remember the ride, but did remember waking up on a couch in a home that wasn't hers. She claimed she later woke up with Armstrong on top of her kissing her; because of his size she was unable to get him off, and she alleges he raped her. She said she passed out during the alleged assault.
Afterwards, she said Luke and another male drove her from his Austin home to hers.
Weeks after making the report, police assisted the victim in making a phone call to Armstrong, in which they said he admitted to having sex with her a few years ago at his dad's house. He said he remembered picking her up on the night, and that he too had been drinking. He also said he remembered asking if they were going to have sex, and that she herself walked to the bed.
Police spoke with at least six people to whom the victim confided in at the time, who in turn relayed she had said she was sexually assaulted; however one friend said the sex was consensual, KXAN reported.
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View StoryInvestigators also spoke with the friend who drove home with the pair that night; he said he did not remember Luke drinking that night, but said the victim hadn't seemed overly drunk either. He said they drove to Luke's house and the two went inside, and that he didn't know what happened after that. However he said the girl later called him to tell him she'd been raped.
Through his attorney Randy Leavitt, Armstrong denied the charges.
"A complete review of the facts will confirm what has been alleged absolutely did not occur and a proper and thorough legal process will exonerate Luke," he said in a statement. "What occurred three years ago in high school was not a crime and was not a sexual assault. It was a consensual relationship then and continued consensually between two young adults, with both ultimately going their separate ways."
"These charges should never have been filed, certainly not three years later. However, thankfully, the Texas court system works and will establish Luke's innocence."
The 21-year-old was released on $75k bond.