By Lauren DiSpirito

BROOMFIELD, Colo. (CBS4) – In February 2015, shortly after Joseph Tumpkin accepted an assistant coaching position with the University of Colorado football program, his then-girlfriend says Tumpkin began beating her at a Broomfield hotel, according to court documents filed in the case and obtained by CBS4.

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The woman told police that from then on, until November 2016 — a period of nearly two years during which Tumpkin worked as a defensive coach for the CU Buffs — the beatings escalated into a continued pattern of violence in which Tumpkin allegedly choked her, pushed her into walls, dragged her by her hair and bit her, the documents reveal.

Last month, Tumpkin, 45, was charged with eight counts of felony and misdemeanor assault. According to the 17th Judicial District Attorney’s Office, the charges allege Tumpkin used his hands as a deadly weapon, strangling and causing bodily injury to his now ex-girlfriend.

Joseph Tumpkin (credit: CBS)

Joseph Tumpkin (credit: CBS)

Tumpkin resigned his position with CU, the university says, at its request. He is due in court in Adams County on the charges on Thursday.

According to the woman, in February 2015 the university was putting Tumpkin up at the Renaissance Boulder Flatiron Hotel where she decided to visit him for the weekend. The two had been dating for about one year, she says, after meeting while he was coaching football at the University of Central Michigan.

The woman suspected Tumpkin may have been cheating on her. When she walked into the Renaissance, she saw Tumpkin at the hotel bar with another woman. Later, in a hotel room, they argued about it and Tumpkin pushed her, choked her and head “butted” her, a complaint filed in the case states.

(credit: CBS)

(credit: CBS)

She told police after the February 2015 incident similar attacks followed, often after arguments inside his apartment in Broomfield, nearby hotel rooms, and during trips to Florida and Illinois.

In all, the woman told police she thinks Tumpkin choked her more than 100 times. On three of those occasions, she says Tumpkin choked her to a point where she could not breathe.

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In March 2016, the court document states one of Tumpkin’s neighbors at his apartment complex on Via Varra Road called 911 after hearing fighting and a woman plead with a man to stop hurting her. According to the document, the neighbor also heard the man tell the woman “I’m going to f****** kill you.” Broomfield police responded, but the woman says she intentionally downplayed what had happened to keep Tumpkin from getting into trouble.

Last week, an article published by Sports Illustrated indicated CU officials may have known about the allegations far sooner than they initially admitted.

Tumpkin’s former girlfriend went to Broomfield police with allegations of domestic violence in December 2016 after she says she told CU head football coach Mike MacIntyre about the violence. Three weeks later Tumpkin was on the sidelines as the team’s defensive coordinator for the Alamo Bowl game.

Joseph Tumpkin (credit: CBS)

Joseph Tumpkin (credit: CBS)

Attorneys for both Tumpkin and the woman did not immediately return CBS4’s interview requests.

University Chancellor Philip DiStefano issued a public apology, saying the victim “should have received an immediate response from the university … ” and calling the case “confusing … as to our reporting requirements under our policy.”

Asked whether the university is conducting its own investigation into how football and athletic department leadership handled the allegations, the campus’s Office of Institutional Equity and Compliance, which is responsible for looking into Title IX complaints, responded by email.

“The OIEC does not comment publicly on any matter that may have been referred to them,” the email states.

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Lauren DiSpirito reports for CBS4 News at 10 p.m. She covers breaking news and feature stories along Colorado’s Front Range. Follow her on Twitter @CBS4Lauren. Share your story ideas with her here.