The former Stanford University swimmer, whose sentence for sexual assault has been widely condemned as too lenient, spoke of drug and alcohol use before entering college, undermining his claims to a judge that he lacked experience with alcohol, court documents show.
Brock Turner, 20, was sentenced by Santa Clara County Superior Court Judge Aaron Persky to six months in county jail after being convicted of sexually assaulting an unconscious woman.
Prosecutors had sought a six-year jail term.
In a letter to the judge before his sentencing, Turner said he did not have experience with alcohol.
"Coming from a small town in Ohio, I had never really experienced celebrating or partying that involved alcohol," according to court documents.
He said in the letter that when he arrived at Stanford, he was encouraged by older members of his swim team and friends to drink during social situations.
"I wish I had the ability to go back in time and never pick up a drink that night," he said in the letter.
Court officials released numerous text messages sent and received by Turner that referenced buying and using marijuana and drinking alcohol before he entered Stanford, the court records showed on Friday.
In June 2014, Turner texted his sister about "raging" the previous night after spending an hour and a half drinking, according to court documents.
That April, he discussed pooling money to buy marijuana with a friend, court records showed.
One of Turner's lawyers, Mike Armstrong, sent a text message to Reuters declining comment on the documents.
Uproar over the sentence was partially fuelled by a letter from Turner's father to the judge that described the assault as "20 minutes of action," and a statement by the victim to the court detailing the January 2015 assault and its repercussions on her life.
It is part of growing outrage over sexual assaults on US college campuses.
Officials have said Persky has received death threats since imposing the sentence, and he faces a possible recall effort led by a Stanford law professor.
Women's advocacy group UltraViolet said it would deliver on Friday a petition with more than 1 million signatures to the California Commission on Judicial Performance, an independent state agency, calling for Persky's removal from the bench.