ABC News October 29, 2015

As Owen Labrie Faces Sentencing, Court Records Reveal New Details of Prep School Sex Assault Case

WATCH: Sentencing in Prep School Sexual Assault Case

The teen at the center of the St. Paul's School "senior salute" sexual assault case, Owen Labrie, was a farm boy attending the elite prep school in New Hampshire on a full scholarship.

A freshman accused Labrie of raping her in May 2014, leading to a trial and his conviction in August on multiple misdemeanor sex crimes and the felony charge of using a computer to lure a minor. That freshman grew up in one of New England's wealthiest families, her father a St. Paul's alum.

This morning, their families are expected to be in the front rows of a Concord, New Hampshire, courthouse once again, this time to learn the fate of now 20-year-old Labrie, who was slated to be a Harvard College divinity school student on full scholarship this year, but instead could be headed to jail and be forced to register as a sex offender, depending on the sentence handed down by a judge today.

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Labrie's mother submitted an impassioned letter on Wednesday to New Hampshire Superior Court Judge Lawrence Smukler, pleading with him to sentence her son to probation. She described watching Owen slip into despair and even become suicidal after his arrest as he watched "so many years of dedication and hard work dissolve before him."

"It is not easy to describe how difficult these eighteen months have been for Owen and our family," Denise Holland wrote, adding that the case has put her deeply in debt. "I am asking you, please, to give him a chance to proceed on with his life and become the productive, spiritual, decent hard-working man of service I know he is destined to be without the stigma of registration or incarceration."

The investigation into a tradition known as the "senior salute" began in June 2014 when St. Paul's Dean of Students Chad Greene asked Concord detectives if the boarding school should alert Labrie that he was the subject of an aggravated felonious sexual assault investigation, according to police reports obtained by ABC News. Prosecutor Catherine Ruffle said in court that the "senior salute" practice was largely intended as a way for graduating seniors "to be with someone that they might have wanted to be with throughout" high school, and could include activities like walking to class together or kissing but "it might include a little bit more."

Jim Cole/AP Photo
The entrance to the elite St. Paul's School is seen, Aug. 14, 2015 in Concord, N.H.

Weeks earlier, according to court testimony and records, the victim agreed to meet Labrie for a "senior salute." Labrie told detectives that "a lot of senior saluting happens between students that don't know each other" and that the school was trying to "put its foot down on this culture," according to the police reports detailing Labrie's interviews with Concord detectives.

"Owen offered that [the victim] is a 'beautiful girl' and that he 'enjoyed' his time with her. He stated that he 'was not going to have sex with her,'" one report states.

When he returned to his dorm after his encounter with the victim, "nasty rumors" began, Labrie told detectives. "He stated that he wanted to 'do his best to calm this storm,'" which became worse when the victim's sister -- whom he had dated and "hooked up with" several times -- tried to hit Labrie and accused him of "taking her little sister's virginity," according to the report.

"This is for taking my little sister's virginity last night," the sister told Labrie as her friends hit him, according to Labrie's interview with investigators. He told detectives he had "a shiner" for graduation as a result.

But it was the Facebook messages exchanged between Labrie and the victim before and after the encounter that led to the most serious conviction against him. Labrie was found guilty of a felony for using a computer to "seduce, solicit, lure or entice a child under the age of 16." That conviction could leave him unable to coach children or live near a school as a registered sex offender.

In one message sent on May 29, 2014, a day before he met with the victim and went to a school rooftop, Labrie wrote, "I want to invite you to come with me, to climb these hidden steps, and to bask in the nicest view." The victim later responded, "only if it's our petit secret," according to court records.

As the two made plans to meet, Labrie texted a friend "I'M SLAYIN" with the victim's name, a reference to his nickname the "Slaymaker" for trying to log the highest number of senior salutes, according to court records. He later bragged he "used every trick in the book" when he finally met the victim for the senior salute, said prosecutors, who noted it was evidence of his intent to take advantage of the underage victim.