A Massachusetts woman is suing Brown University, saying that administrators at the school acted indifferently and failed to adequately investigate when she reported being raped by three students on Brown’s football team.

The lawsuit, filed Monday in federal court in Rhode Island, said authorities later found explicit photos of one of the accused students with the woman at the time of the assault, along with text messages that appeared to show the students laughing about the reported rape hours later.

The school opened an investigation, but never finished it and never doled out any punishment, the suit said.

“I don’t know how a school can do nothing with this kind of evidence,’’ said one of the woman’s attorneys, Wendy Murphy, who is based in Boston. “I’m literally speechless. I don’t have an answer.’’

A Brown spokesman said officials were “confident’’ in the decisions the university had made in the case and noted that a grand jury had declined to bring criminal charges in the case.

It was at least the third time in as many years that reported sexual assault victims had accused Brown of not properly investigating their claims.

In addition to seeking an undisclosed amount of monetary damages, the suit demands that Brown issue a declaration that it violated the woman’s rights, and that, in general, the school’s sexual misconduct policy does not comply with federal law.

“As a matter of policy and procedure, Brown was systematically not adequately investigating these types of cases,’’ Murphy said. “Brown had adopted a policy that in and of itself was subjecting women to second-class treatment.’’

The suit said that the reported rape occurred on Nov. 21, 2013, after the woman, then a freshman at Providence College, was drugged without her knowledge while socializing at a Providence area bar.

She was then taken by taxi to a dormitory on Brown’s campus, where she was sexually assaulted, the suit said.

Nine days later, the woman went to a hospital for treatment. On or around Feb. 3, 2014, she reported being raped to police in Providence and at Brown, the suit said.

The suit did not name the woman or her alleged assailants, instead referring to her as Jane Doe and the Brown students as Students A, B, and C.

The Brown students’ cellphones were later seized by police, the suit said, and text messages between Students A and B were discovered.

According to the suit, one message sent at 6:14 a.m. on Nov. 22, 2013, said, “. . . yo like classic [Student C] tho . . . no invite just walks in and starts raping her.’’

In another text that afternoon that appeared to refer to the incident, one student said he was “LMAO,’’ text lingo for laughing.

Data from Student A’s cellphone also revealed explicit photographs of the woman with Student B, taken at the time of the reported assault, the suit said.

And, the suit alleged, tests of her hair were later found to be positive for drugs commonly used to incapacitate rape victims.

In the spring of 2014, Brown ordered two of the students, both freshmen, to leave campus, the Providence Journal reported. A criminal case against the two students ended in August 2014 when a grand jury declined to indict them.

In the fall of 2014, two of the three students connected to the reported assault returned to Brown, according to the Brown Daily Herald student newspaper. The other withdrew.

At around the same time, and after the woman’s urging, Brown administrators told her they would investigate under the school’s student disciplinary code. The suit said that the code did not comply with Title IX, a law that prohibits gender discrimination in federally funded education programs and requires certain steps be taken to investigate claims of sexual violence.

The woman filed a Title IX complaint in October 2014 with the US Education Department, which is still investigating, according to the suit.

The woman later dropped out of Providence College. She “was in fear for her safety and well-being on campus and in the general Providence area,’’ the suit said.

This past June, after the woman requested an update from Brown about her case, university officials told her they had never completed the investigation and no disciplinary action had been taken, the suit said.

In a statement Thursday, Brown spokesman Brian Clark said, “Brown takes every allegation of sexual misconduct seriously, including the allegations made by Jane Doe.’’

“We are confident in the decisions made at Brown related to Jane Doe’s allegations and we will respond as appropriate through the legal process,’’ he added.

Amid a surge of activism, campus sexual assault has been in the spotlight nationally in recent years, including at Brown. Critics have raised concerns that sexual assault, particularly when athletes or fraternity members are accused, is not being taken seriously enough in both criminal and student disciplinary proceedings.

In a separate case, a former Brown student last month filed a suit against the school, saying it mishandled an investigation into her report that she was drugged at a fraternity party in the fall of 2014 and later sexually assaulted.

That suit raised the question of whether the university dropped a disciplinary proceeding against the student accused of drugging her to protect him because he was the son of a trustee, the Associated Press reported. Brown has denied it was a factor.

That case sparked student protests, and the university stripped the fraternity of its university recognition for 2½ years.

In another case, a Brown student said in April 2014 that she had been sexually assaulted and choked by another student in August 2013.

The woman said her attacker was found responsible by the school and given a one-year suspension, which she said was too lenient, prompting her to file a complaint against the school, which the federal Education Department is still investigating.

The accused student has denied that he choked her and said he believed the sex was consensual.

As of Nov. 9, the federal Education Department was investigating 284 sexual violence cases across 216 colleges nationwide.

Matt Rocheleau can be reached at matthew.rocheleau @globe.com. Follow him on Twitter @mrochele.