Patrick Ell didn’t have to stake out the Portland, Ore., house for long, police say, until he saw his target. As the man — an old colleague of his — walked inside, the 52-year-old Ell allegedly rushed at him, beat him over the head with a baseball bat and then chased the man down the street.

Matthew Rygg, who would need 18 staples to the head, told officials he thought he was being murdered.

Police now say the attack Friday was the shocking action of a protective father so furious about how Rygg, a top college administrator, had handled his daughter’s sexual assault claim that he brutally attacked the university official.

Ell has now been charged with felony second-degree assault and reportedly banned from the University of Portland, where the two worked.

Michael Lewellen, a spokesman for the university, told The Washington Post that Rygg had been released from the hospital and was “healing at an undisclosed location.” He declined to comment further, citing an active criminal investigation.

Ell’s attorney, Stephen Houze, did not immediately respond to a request for comment.

The two men had known each other for years, police say, working together as administrators at the University of Portland, a small Catholic school on the banks of the Willamette River. Since 2009, Ell had worked at the school’s community service center, leading social justice talks and a “rural immersion” in Washington state’s Yakima Valley. Rygg had been hired three years ago to oversee the dorms, health and counseling services, community service — and, at one point, Title IX procedures.

On Sept. 30, 2016, Clara Ell, then 18 and a first-year student at the university, had gone to a women’s lacrosse club party with some friends, both she and her father said. Clara would tell reporters she drank so much — shots of tequila, bags of cheap wine, swigs of whiskey — that she blacked out, and her friends had to walk her home.

As her roommate fed her snacks, she received a text from a classmate, a male student with whom she had been in a “short-lived romantic relationship,” asking to see her.

“Tonight is not the best idea,” Clara said in a text message, which she showed to multiple news outlets, later adding: “I’m drunk haha and who knows what I’ll say or do.”

But the male classmate showed up anyway, and she said what followed was a hazy blur: letting him into her dorm room. Her clothes coming off. Putting a condom on a bedside table, and realizing he had been forcibly penetrating her — even after she said “no.”

A week later, she reported the incident to the university and went through its formal conduct hearing process, her father would say. She did not go to the police initially, he said, because she only wanted her alleged assailant to get suspended or expelled, rather than ending up in jail.

But according to Clara’s account, school officials determined there was not enough evidence to find him responsible for sexually assaulting her. She was intoxicated — but not incapacitated, they told her in a letter, and her behavior that night was “consistent” with her past contact with the male student. (The university has never released its formal findings, and it is barred from doing so under student privacy laws.)

Clara was livid. In a statement to administrators later in the fall of 2016, she denied that she and the man had been “friends with benefits.” She accused her school of failing to support her and failing to act as “a safe environment where violence is not tolerated.” She appealed the decision — unsuccessfully.

“To turn to the University that I trust and that I love and have them tell me, ‘No, this didn’t really happen to you,' ” she told the Beacon student newspaper in December 2016. “It’s scary.”

Yet, if Clara was angry with the university, police say her father was more infuriated. After graduating from the university in 1989, he raised Clara and her siblings on campus, she said, taking them to soccer games decked out in school colors.

The case seemed to change that passion for his alma mater, according to officials. Ell was upset with the university for failing to hold the man accountable, one school official later told police, but he was especially angry with Rygg.

“We spend a lot of time talking about what gender-based violence is and what to do if you or someone you know is impacted. That is vitally important and we need to continue raising awareness about these important issues,” Rygg said on the school’s website. “These conversations are not easy, but we must go there together.”

As Clara went public with her story, Ell sent out an email to dozens of people at the university, blasting the misconduct process. He was alarmed it had taken so long — 16 days — for her to get a response after requesting a student conduct hearing, the Beacon reported. He insisted that Clara was so drunk she wasn’t able to give consent.

“We found the hearing process to be horrible,” Ell would later write on Facebook. “I ask for your prayers for everyone at the University of Portland. I am afraid that many more students may suffer sexual assault.”

By May 2017, father and daughter would both call it quits. He resigned from his job, and she transferred to the University of Oregon.

In the meantime, Clara’s case quickly emerged as a local flash point in the national conversation over sexual assault on campus. Like many other colleges at the time, the University of Portland had been facing particularly heightened scrutiny over its Title IX policies.

Upon hearing her story, the Beacon newspaper wrote an editorial berating administrators over their response to Clara’s sexual misconduct complaint. Her allegations became the subject of a lengthy 2017 feature in Vice, on alcohol and consent. At least one school official quit, as students and parents alike bemoaned the school’s Title IX investigations as opaque and unfair.

Around the country, administrators drawing that kind of flak — from all sides of the issue — have found themselves in the knotty position of defending their policies. Outside of Oregon, they’ve been protested, sued, deposed and even shouted down in the middle of lectures. None of that blowback led to bloodshed.

It’s unclear what exactly prompted Ell to allegedly resort to violence.

On Friday evening, he and his wife were at a Christmas party that Ell decided to leave by himself at about 9 p.m., police said. In the years since quitting his job at the University of Portland, he had been emailing Rygg and sending him nonthreatening messages over Facebook, all the way through September.

Minutes later, a bystander told police she saw one man beating another, who was bleeding heavily after having been struck on the head. Rygg was taken to a hospital with several lacerations to his head.

By 9:30 p.m., Ell was back at home, where officers found him watching TV with his family and arrested him. After being released from jail Saturday, he was arraigned Monday, with another court date set for Dec. 31.