A civil rights investigation will examine the Police Department’s special victims division, which has long faced troubling accusations from people who reported assaults.The Department of Justice has opened a sweeping investigation of the New York City Police Department’s Special Victims Division and its handling of sex crimes, officials said on Thursday.Prosecutors in New York and Washington will examine allegations of officers “failing to conduct basic investigative steps and instead shaming and abusing survivors and re-traumatizing them during investigations,” according to a Justice Department news release. They will investigate the division’s policies, procedures and training, and evaluate interactions among officers, victims and witnesses.The department had received allegations of deficiencies in the unit “that have persisted for more than a decade, depriving survivors and the public of the prompt, thorough and effective investigations needed to protect public safety,” the release said.The federal probe is another setback for the Police Department, which is already under consent decrees governing its stop-and-frisk and surveillance practices. The state attorney general has also sued to install a monitor to oversee changes in the way the department handles protests after finding evidence of widespread abuse during the George Floyd social justice demonstrations in 2020.The announcement came 10 months after more than a dozen women wrote a letter to the Department of Justice calling for an investigation of the division. Many had spoken out for years about their experiences with investigators who they said lacked sensitivity, skill and time to properly investigate their cases, even after the #MeToo movement forced a cultural reckoning on rape.Leslie McFadden, one of the signers, said Thursday she was “ecstatic” that the Justice Department had decided to act. Police officials have acknowledged botching the investigation into her report that a former colleague drugged and raped her in October 2015.“So many survivors have been robbed of justice, and they’ve been waiting in vain for many years now,” Ms. McFadden said. “Although this is just a first step, it’s a step in the right direction and a modicum of justice for all of the survivors who have been wronged by the N.Y.P.D.”Keechant Sewell, New York’s police commissioner, said in a statement Thursday that she believes investigators will find that the department “has been evolving and improving,” adding that she wants the Special Victims Division to serve as “the national model.”“But we will be transparent and open to criticism,” Commissioner Sewell said.Paul DiGiacomo, the head of the Detectives’ Endowment Association, whose members include sex-crime investigators in the division, did not immediately return a request for comment.The federal investigation followed decades of complaints from women who charged that they were maligned and dismissed after reporting rapes and sexual assaults. Indeed, four years ago, a city Department of Investigation audit found crippling deficiencies in the division’s staffing and training — echoing a similar report in 2010.The 2018 audit found that police leadership had prioritized rapes in which the perpetrators were strangers over those in which assailants knew their victims. Investigators said in the report that the division’s own commanders repeatedly warned top department officials that the unit was failing not only victims of sex crimes, but also of child abuse.The Police Department, which was already facing scrutiny of its handling of sex-crimes allegations against the Hollywood producer Harvey Weinstein, initially resisted the findings of the audit and refused to implement many of its recommendations. Officials later changed course, though many of the suggested reforms — including staffing recommendations — have yet to be put in place.On Thursday, federal officials said the time for change is now.“Victims of sex crimes deserve the same rigorous and unbiased investigations of their cases that the N.Y.P.D. affords to other categories of crime,” Damian Williams, the U.S. attorney for the Southern District of New York, said in the news release. “Relentless and effective pursuit of perpetrators of sexual violence, unburdened by gender stereotypes or differential treatment, is essential to public safety.”The investigation, which will be conducted jointly by federal prosecutors in Brooklyn and Manhattan, follows five similar probes that the Biden administration has opened since April 2021, as federal prosecutors become increasingly aggressive in examining whether law enforcement agencies engage in excessive force, biased policing or other unconstitutional behavior. They have intensified scrutiny on deaths at the hands of officers, including in Minneapolis, the site of Mr. Floyd’s murder, and in Louisville, Ky., where the police department’s actions during Breonna Taylor’s shooting death are under investigation.The inquiry into the New York Police Department represents the first undertaken during Attorney General Merrick B. Garland’s tenure that focuses on gender discrimination claims, rather than race.Jane Manning, a former city prosecutor who now works to help rape survivors across the country, said Thursday’s announcement showed that the Justice Department understood the gravity of the failures.“For too many years, survivors of rape and sexual assault have come forward to report these crimes, only to encounter apathy and incompetence from investigators who should be setting an example for the world,” said Ms. Manning. “For the Justice Department to investigate the N.Y.P.D. for failing rape victims says that the Justice Department gets it.”The announcement on Thursday had been months in the making. Last fall, federal prosecutors spent weeks interviewing more than a dozen victims and their advocates about their experiences with the division.Michael Osgood, who led the Special Victims Division for eight years, said the federal investigation is an indictment of Mayor Bill de Blasio and the senior Police Department leaders who worked under him. Last year, Mr. Osgood, who was removed in 2018, sued the administration; he and many advocates believe he was forced out for cooperating with the Department of Investigation audit. The report relied on dozens of his memos to senior officials.The mayor and his subordinates “for years were fully informed of the root causes of the Special Victims system failures and did very little to fix them, and in fact they made it worse,” Mr. Osgood said. “They disgraced themselves and brought shame on a venerable department. Now there is hope.”Mr. de Blasio did not immediately return a call seeking comment.Mayor Eric Adams said at a news conference Thursday that he welcomed the latest review. “There is no higher level of priority for us than to ensure that victims of sexual assault receive the right treatment, investigation and resolution,” he said.While many welcomed the federal investigation in New York, some victims felt conflicted.Alison Turkos had reported to police that she was kidnapped, held at gunpoint and raped in October 2017 by a Lyft driver and two other men. Federal investigators took over the case after her receipt showed she had been taken across state lines. The announcement Thursday came less than a day after she learned that they would not bring charges.“There’s so many of us, myself included, who won’t even get a semblance of justice or accountability because the legal system failed us miserably, because we did what we’re supposed to do,” she said, describing how she had eagerly helped investigators. “It feels like a slap in the face.”Glenn Thrush